CHAPTER 4

ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES

4.1 COMMUNITY IMPACTS

The East Span Seismic Safety Project (East Span Project) does not lie within the boundaries of any established residential neighborhood. Land within the project area is under institutional, residential, and commercial use. Project alternatives were analyzed for potential impacts to local communities, including impacts on employment; community services; potential for displacement of residences, businesses, or public facilities; and consistency with existing land uses and development policies.

4.1.1 Social and Economic Impacts

Project alternatives were analyzed for potential social and economic impacts. Socioeconomic impacts are considered to occur if a project:

• Induces substantial growth in a community or prohibits desirable growth;
• Places demands on community facilities;
• Disrupts existing patterns of interaction in a neighborhood; and
• Affects a low-income or minority community.

The East Span Project is not expected to have adverse social or economic impacts on established neighborhoods or communities because of the project’s location in an institutional and industrial setting with limited residential use and because the alternatives do not change existing transportation capacity. Any project-related changes to social or economic conditions in Bay Area neighborhoods or communities are expected to result from the employment impacts of the large construction labor force that would be needed to construct the build alternatives.

Employment

Project build alternatives would generate demand for workers during the construction period. Construction would have a positive impact by generating direct construction jobs and spin-off service employment opportunities within the region. Workers are expected to be recruited from the local labor force, with specialty skills being provided by workers from inside and outside the region.

The Bay Area has a large labor force and strong economy; thus, it is expected that the vast majority of the construction labor force would be workers already living in the area. However, some specific work, such as bridge iron work, can only be done by a limited number of national contractors, resulting in a need to import specialist workers. In a worst-case scenario, in which there are many major construction projects occurring concurrently (compared to the base level), a shortfall of construction workers could develop in the region.

If a shortage developed, other workers would commute from outside the region (Central Valley) or take up temporary residence. Temporary construction workers often rent rooms stay in motels, or seek other types of temporary housing during the work week, leaving their families behind. In addition to motels and rooms, there are more than 700,000 rental units within the Bay Area. Although there is a low vacancy rate in the Bay Area, the potential impact of the project labor force would not be noticeable on the housing market. The Bay Area is a large and dynamic region. At any given time, some companies and agencies are reducing their labor force while others are increasing. There is a movement of workers and households in and out of the Bay Area at all times, and the demand generated by East Span construction activities would not cause an adverse impact on the general availability of labor supply, the housing market, or school enrollment.

Construction materials, such as steel and concrete, are not produced in the project vicinity and are likely to be purchased from other areas. Thus, the local primary economic benefits of the project would be the direct construction jobs and the economic multiplier caused by local spending of the construction labor force. The Association of Bay Area Governments (ABAG) estimates that the number of local secondary jobs created is 1.44:1 construction job. Because the region has a large design and engineering labor force, this effect is likely to occur locally as well, providing additional labor jobs.

No-Build Alternative. The No-Build Alternative would not generate additional employment opportunities because no construction work beyond the prior Interim Retrofit Project would be undertaken.

Retrofit Existing Structure Alternative. Engineering design and construction of the Retrofit Existing Structure Alternative are expected to generate approximately 2,356 total person years of employment not otherwise predicted for the Bay Area economy (see Table 4.1-1). A forecast of construction workers required to retrofit the existing East Span, by trade, assumes 60 iron workers, 60 pile drivers, 100 operating engineers, 60 carpenters, 40 concrete finishers, 40 laborers and miscellaneous workers.

Sources: Caltrans, September 1998.

Assumptions: ^(a) 19% of construction cost = labor @ $95,000/person year (includes overhead).

^(b) 100% of design & engineering = labor @ $125,000/person year.

^(c) High range of cost estimate for this alternative is presented in Table 2.4-1.

Note: The cost information in this table represents the estimated cost of the various alternatives based on information available in 1998. They do represent the current costs of the alternatives, which would be greater, but still have the same relative relationship. See Section 2.4.2 — Costs for more information.

Replacement Alternatives

A forecast of construction workers required to construct a replacement bridge was estimated based on average annual employment of 600 people over the estimated seven-year construction period, which includes dismantling the existing bridge. (The number of employees required would increase if the construction period is shortened.) Estimated direct labor by trade is: 102 iron workers, 100 pile drivers, 168 operating engineers, 100 carpenters, 65 concrete finishers, and 65 laborers and miscellaneous workers. With a peak period of two years for structural work on a new bridge, a peak demand of approximately 175 iron workers would be required.

Replacement Alternatives N-2, N-6 (Preferred), and S-4 are each calculated to generate slightly more than 4,000 total person years of employment over the construction period (see Table 4.1-1).

Impacts of Build Alternatives. Build alternatives would generate direct and indirect labor demand during a period lasting up to seven years. Workers are expected to be drawn from the regional labor pool with specialty trades generating demand from outside the Bay Area. A portion of the specialty trades may be attracted to the Bay Area for the duration of the project. Because of the large Bay Area economy, consisting of approximately three million jobs, worker-generated demands for housing or community services are not expected to have a noticeable effect on San Francisco, Oakland, or other Bay Area community housing stocks or services. The project is expected to have a beneficial impact on San Francisco and Oakland economies by generating direct and indirect jobs. The community would benefit through direct and secondary employment opportunities and no mitigation is required.

San Francisco (Yerba Buena Island). Construction of the Retrofit Existing Structure Alternative and replacement alternatives all have the potential to cause temporary impacts to residents on Yerba Buena Island (YBI), including USCG housing and occupied former Navy housing. (See Section 4.14 — Temporary Impacts during Construction Activities for more details.) There would be no permanent impacts.

Oakland. A construction staging area could be built at the former Oakland Army Base (OARB). Construction activity would not affect neighborhoods in West Oakland. Because the project would be built within San Francisco Bay, there would be no impacts to community cohesiveness or other permanent impacts to West Oakland neighborhoods.

4.1.2 Community Services

No impacts to community services were identified under any of the categories: utilities, fire protection services, and police services. Permanent utility service would not be disrupted by the project (see Section 4.12 — Utilities Relocation for more details); police and fire protection services would not change as a result of the project, and access to the Treasure Island (TI) elementary school would not be affected by the project.

One of the columns of Replacement Alternative S-4 would be placed on the East Bay Municipal Utility District (EBMUD) pipeline that feeds into the dechlorination facility on the Oakland Touchdown. If Replacement Alternative S-4 is carried through to final design, the column could be moved to avoid the pipeline. However, even if the column is relocated under Replacement Alternative S-4, there would be insufficient vertical clearance between the bridge structure and the road used by large chemical supply tractor-trailer trucks to serve the dechlorination facility. To maintain EBMUD's access to its facility, the road, the facility, or both would need to be relocated (see Section 4.1.4 — Impacts to Existing Land Use for further details).

4.1.3 Environmental Justice

There are no identified minority or low-income populations or communities in the project area. (FHWA defines populations as "readily identifiable groups or clusters of minority persons and/or low-income persons who are in the project study area.") Outside the project area limits on TI and in West Oakland there are communities which are comprised of minority and low-income populations.

Title VI Policy Statement

Appendix L contains Caltrans policy regarding compliance with Title VI of the Civil Rights Act of 1964, the Civil Rights Restoration Act of 1987, and Title 29 CFR Part 21.

No-Build Alternative

There would be no change in the existing environment in the neighborhoods outside of the project area limits.

Retrofit Existing Structure and Replacement Alternatives

Only minimal impacts are expected on the TI community. During construction of the project, temporary changes in access and bridge closures would affect mobility of the TI community. Caltrans is continuing to investigate the number and timing of partial or full bridge closures in an effort to simultaneously minimize public inconvenience, facilitate construction and maximize public safety. Short-term closures would be timed during off peak hours and Caltrans would implement a traffic management plan to manage impacts to traffic. Those who live or work on TI would be notified of any bridge closures or changes in access through signage and possibly direct mailings. Final notification procedures would be determined through the Traffic Management Plan.

Emergency access to TI/YBI would be provided at all times.Communities in West Oakland are not expected to encounter any traffic or access problems or other adverse impacts from the project.

As indicated in Section 4.1.1 — Social and Economic Impacts, construction of any of the build alternatives could provide increased employment opportunities from which both the TI and West Oakland neighborhoods could benefit. In addition, the benefits of the completed project including improved traffic operations and safety, would be provided to all adjacent neighborhoods.

It was determined that there are no minority or low-income populations in the project area that would be adversely affected by the East Span Project. Based on the environmental analysis in other sections of the FEIS, the Preferred Alternative or other build alternatives would not cause disproportionately high and adverse impacts (including any indirect impacts) on minority or low-income populations outside the project limits.

4.1.4 Impacts to Existing Land Use

This section describes changes in land use that would occur as a result of the project alternatives.

Changes in Land Use

Potential project-related changes to existing land uses on YBI and at the Oakland Touchdown are summarized in the following section. Permanent impacts are addressed here. Short-term construction-period impacts are addressed in Section 4.14 — Temporary Impacts During Construction Activities.

Land Use Impacts on Yerba Buena Island.

No-Build Alternative. Implementation of the No-Build Alternative would not cause a change in any existing land uses on YBI. No impacts would result and no mitigation would be required.

Retrofit Existing Structure Alternative. With the exception of temporary impacts during construction, the Retrofit Existing Structure Alternative would not cause any changes to existing land uses in the project area. The footprint of Columns YB1, YB2, YB3, YB4, and E1 would be expanded in size but would remain in their current locations. Because the towers and cross-members would be encased in concrete, current views through the towers would be blocked (refer to Figure 4-15a in Appendix A and see Section 4.3 — Visual Impact Analysis). No new columns would be constructed on the island. No permanent impacts would result from the retrofit alternative and no mitigation would be required.

Replacement Alternatives. The new bridge structure for each replacement alternative would begin east of the YBI tunnel portal. The areas of impact for each of the three alternatives overlap. Many of the same buildings on the eastern edge of the island would be affected by all of the alternatives.

Replacement Alternative N-2. Replacement Alternative N-2 is positioned to the north of the existing East Span. The alternative would place 26 bents between the YBI tunnel eastern portal and the eastern end of YBI. The alternative would also require construction of temporary detours to be used while the viaduct is retrofitted and transition structures on YBI are constructed. (Refer to Appendix A for alignment and temporary detour drawings.) Impacts of the temporary detours are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

An existing road providing access to the northeast end of the island would be blocked (see Section 4.2.1 — Vehicular Circulation and Access). The alternative would not remove existing structures or block access to existing uses on the island.

Replacement Alternative N-2 would cross approximately 53 meters (175 feet) above the ground at vacant Navy Building 262, but would not place columns at locations which would obstruct future access to the building. Navy Building 213 (fire truck storage) would be removed to allow for construction of the temporary detours (which would require placement of a column through the building.) The alternative would be approximately 10 meters (33 feet) closer horizontally to Quarters 1 than the existing East Span (i.e., approximately 40 meters [130 feet] south of Quarters 1). However, the proximity of the span would not affect access to this building or place the columns permanently within the boundaries of the Senior Officers’ Quarters Historic District.

Replacement Alternative N-2 would displace Buildings 30 (storage), 40 (administration), 75 (storage), and 270 (vacant) to relocate the USCG access road and gate and Building 213 to allow for temporary detour construction. Construction of Replacement Alternative N-2 would require that the existing access road and gate to the USCG facility be moved south. Replacement Alternative N-2 has not been identified as the Preferred Alternative.

Mitigation:

If Replacement Alternative N-2 were constructed, Caltrans would work with the USCG and Navy to provide replacement buildings of like size, construction, construction materials, and quality, built to current code requirements for Buildings 30, 40, 75, 213, and 270. The USCG and Navy would need to provide suitable sites for the replacements outside state right-of-way.

Replacement Alternative N-6 (Preferred). Replacement Alternative N-6 is located to the north of the existing East Span in an alignment similar to Replacement Alternative N-2. The alternative would place approximately 19 bents between the eastern portal of the YBI tunnel and the eastern edge of YBI. The alternative would require construction of temporary detours to be used while the viaduct is retrofitted and transition structures on YBI are constructed. (Refer to Appendix A for alignment and temporary detour drawings.) Impacts of the temporary detours are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

Replacement Alternative N-6 would cross approximately 53 meters (175 feet) above the ground at vacant Building 262, but would not place columns at locations which would obstruct future access to the building. Building 213 (fire truck storage) would be removed to allow for construction of the temporary detours. The alternative would be approximately 10 meters (33 feet) closer horizontally to Quarters 1 than the existing East Span, which is approximately 40 meters (130 feet) south of the building. However, the proximity of the span would not affect access to the building or place columns permanently within the boundaries of the Senior Officers’ Quarters Historic District.

Replacement Alternative N-6 would displace Buildings 30, 40, 75, and 270 to relocate the USCG access road and gate and Building 213 to allow for temporary detour construction. Construction of Replacement Alternative N-6 would require that the existing access road and gate to the USCG facility be moved south.

Mitigation:

If Replacement Alternative N-6 were constructed, Caltrans would work with the USCG and Navy to provide buildings of like size, construction, construction materials, and quality, built to current code requirements for Buildings 30, 40, 75, 213, and 270. The USCG and Navy would need to provide suitable sites for the replacements outside state right-of-way.

Replacement Alternative S-4. Construction of Replacement Alternative S-4 across YBI would require 24 bents between the eastern portal of the YBI tunnel and the eastern shoreline of the island. Temporary detours would be required on YBI during construction.

Replacement Alternative S-4 would displace Buildings 30, 40, 75, and 270 to relocate the USCG access road. Replacement Alternative S-4 would be located approximately 50 meters (164 feet) from Quarters 1, which is 10 meters (33 feet) farther than the existing East Span, and 60 meters (190 feet) from Navy Building 262.

Mitigation:

If Replacement Alternative S-4 were constructed, Caltrans would work with the USCG to provide buildings of like size, construction, construction materials, and quality, built to current code requirements for Buildings 30, 40, 75, and 270. The USCG and Navy would need to provide suitable sites for the replacements outside state right-of-way.

Land Use Impacts at the Oakland Touchdown Area. Replacement Alternatives N-2 and N-6 touch down to the north of the existing East Span while Replacement Alternative S-4, the southern alternative, touches down south of the existing structure.

No-Build Alternative. Implementation of the No-Build Alternative would not cause a change in any existing land uses in the Oakland Touchdown area. No impacts would result and no mitigation would be required.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would not cause any changes to existing land uses in the Oakland Touchdown area. The bridge footprint would be modified only to increase the size of Column E23 at the western end of the touchdown area. No permanent impacts would result from the retrofit alternative and no mitigation would be required.

Replacement Alternatives.

Replacement Alternatives N-2 and N-6 (Preferred). Replacement Alternatives N-2 and N-6, located to the north of the existing span, would have a similar approach to the Oakland Touchdown area. The northern alternatives would require the permanent displacement of 0.2 hectare (0.5 acre) of land north of the existing bridge that the City of Oakland has designated as Resource Conservation Area.

Replacement Alternative S-4. As shown in Figures 2-11.4 and 2-11.5 in Appendix A, Replacement Alternative S-4 would occupy the westernmost portion of the vacant OARB land to the south of the existing East Span and open storage areas just north of the vacant OARB land used by Caltrans.

Replacement Alternative S-4 is currently designed to place a column in the pipeline east of the EBMUD dechlorination facility. While the column could be redesigned to avoid the pipeline, the vertical clearance between the structure and the service road is insufficient to allow for delivery vehicles to the dechlorination facility. Consequently, if Replacement Alternative S-4 were selected, there would be a conflict with the facility.

Several solutions were evaluated to possibly eliminate the conflict. They include:

• Relocating the existing access road far enough south to provide sufficient vertical clearance beneath the roadway. This would require placing additional fill in the Bay to build the roadway. The area of new fill would be approximately 0.36 hectare (0.9 acre) and the volume would be approximately 13,650 cubic meters (18,000 cubic yards);

• Lowering the grade of the existing service road to create a tunnel beneath Replacement Alternative S-4. The high water table at the Oakland Touchdown would make the tunnel susceptible to flooding and require a pump system to keep the service road open at all times. Caltrans would likely incur ongoing responsibilities for maintaining the tunnel roadway and facilities;

• Building an overpass structure over Replacement Alternative S-4. The overpass structure would add an additional roadway structure near the western end of the Oakland Touchdown area that would block Bay views for motorists, pedestrians, and bicyclists;

• Relocating the dechlorination facility to the north would require the relocation of at least a part of the onshore pipeline while keeping it operational at all times and preventing accidental discharge of effluent. This would still require the service road to be routed under or over Replacement Alternative S-4;

• Relocating the dechlorination facility to the south would require the relocation of part of the onshore pipeline while keeping it operational at all times and preventing accidental discharge of effluent. The relocation would also require additional fill in the Bay for support of the facility;

• Relocating the dechlorination facility to the west would require additional fill in the Bay to support it and would still require the service road to be routed under or over Replacement Alternative S-4; and

• Relocating the dechlorination facility to the east of Replacement Alternative S-4 would reduce the distance over which the effluent is treated. This would reduce the chlorine contact time. EBMUD's discharge operations would need to be modified to provide the same treatment to the effluent over a shorter distance to meet the requirements of EBMUD's permit from the Regional Water Quality Control Board limiting coliform in the effluent.

Mitigation:

If Replacement Alternative S-4 were constructed, Caltrans would work with EBMUD to relocate the service road and/or the dechlorination facility to maintain EBMUD's operations. Caltrans would obtain necessary permits/permit amendments, fund relocation costs, and implement any necessary mitigation. Caltrans would assure continual operation of EBMUD's discharge system during relocation.

4.1.5 Development Trends

The purpose of this section is to evaluate the relationship between the proposed project and anticipated development trends at YBI and the Oakland Touchdown area.

Yerba Buena Island/Treasure Island Draft Reuse Plan Consistency

The Treasure Island Draft Reuse Plan (1996 Draft Reuse Plan) includes "minimum" development scenarios, based upon the existing traffic capacity and access and a guiding policy for development of Naval Station Treasure Island, which states that development should be limited to uses for which access can be accommodated primarily by ferry.

Vehicular access is a major constraint to development on YBI/TI. The East Span Project would not increase the SFOBB’s capacity nor would it improve the access points from the SFOBB to YBI/TI. The eastbound on-ramp to the SFOBB would be replaced with a ramp that provides a standard acceleration lane as opposed to the current stop-sign design, resulting in improved eastbound access to the bridge from YBI.

The 1996 Draft Reuse Plan envisions that development of YBI/TI would occur in five phases. Each phase would build on the previous phase in order to generate the revenue necessary to make needed infrastructure improvements. In turn, this infrastructure would allow for more intensive development in subsequent phases. The phased implementation process is projected to extend over a period of 35 years. Development on YBI is envisioned to occur within the first three phases of plan implementation, which are projected to occur over a 15-year period. To the extent the implementation plan was premised on release by the U.S. Navy and CCSF of a final NEPA/CEQA document several years ago, the phasing schedule appears to be approximately three years behind schedule, as the U.S. Navy and CCSF have not yet released the draft NEPA/CEQA document.

Planned development near the bridge on YBI includes a 5,600-square meter (60,000-square foot) conference center, 13 artisan cottages, and 75 live/work units. This development is in Phase 3 and is scheduled to begin in 2007. The three implementation phases affecting YBI are summarized below.

Phase 1

Phase 1 was anticipated to begin in 1997 and continue through 2001 as closure of the base occurred. In this phase, limited interim uses of the existing facilities are planned. On YBI, Phase 1 assumes that all of the existing buildings would continue in civilian uses, including provision of housing for the homeless and use of Quarters 1 through 7 as a conference/ meeting center. (Note: Housing for the homeless is now in process on TI. No housing for the homeless is planned for YBI.)

Phase 2

Phase 2 improvements are listed in the 1996 Draft Reuse Plan as scheduled to occur between 2002 and 2006. Phase 2 envisions the beginning of improvements to the TI shoreline, including causeway reinforcement between TI and YBI and creating a secure land link to the SFOBB and the proposed ferry terminal on TI. After infrastructure improvements are made, a theme park, sports complex, maritime administration, and expansion of the film studios on TI are proposed as part of Phase 2.

On YBI, Phase 2 includes redevelopment of the existing housing on the west side of the island for housing and hotel uses.

According to the 1996 Draft Reuse Plan, expansion of the Treasure Island Marina was originally scheduled for Phase 2 development. Since the plan was written, the marina project has been accelerated and is currently in the planning stage (see Figure 4-23 in Appendix A).

Construction of the Treasure Island Marina is scheduled to begin in mid to late 2001, after approval of the final plan, preparation and approval of the environmental document, and acquisition of permits.

Phase 3

Phase 3 improvements are listed in the 1996 Draft Reuse Plan as scheduled to occur between 2007 and 2011, which is after completion of the East Span Project (2006). Consequently, there would be no construction conflicts between the two projects. In Phase 3, improvements would be made to stabilize the eastern shoreline on TI, which would allow completion of the theme park. Development of a hotel/retail area is also envisioned in this phase.

On YBI, Phase 3 improvements would include development of the conference center and artisan cottages on the eastern end of the island.

The development potential of YBI would be affected but not precluded by the physical location of the project. Due to the steep topography of most of the island, the eastern end is considered by the CCSF to be the only viable location for development. Also, because the 1996 Draft Reuse Plan will be subject to a number of environmental and regulatory reviews prior to its implementation (including a BCDC federal consistency determination and permit, discussed in Section 4.1.6 — Adopted Goals and Policies), the amount and location of new development on the eastern end of YBI may vary widely from the current development concepts. An analysis of the impacts on the development trends on YBI is described below.

No-Build Alternative. The No-Build Alternative would not conflict with the 1996 Draft Reuse Plan development scenarios, although vehicular access to and from the East Bay could be affected in the aftermath of a major earthquake.

Retrofit Existing Structure Alternative. Expansion of existing East Span columns on YBI would not conflict with redevelopment scenarios for YBI. Since the 1996 Draft Reuse Plan was developed with the bridge in its current location, the conceptual land uses proposed in the plan could be developed under the Retrofit Existing Structure Alternative.

The Retrofit Existing Structure Alternative is consistent with the 1996 Draft Reuse Plan in that it does not include modifications to YBI on- and off-ramps that would change the capacity of existing vehicular access. YBI ramps are not owned by Caltrans and are not critical to providing a lifeline connection in the project corridor. Therefore, the retrofit alternative would not conflict with the transportation access assumptions of the 1996 Draft Reuse Plan.

No long-term impacts would result from implementation of the Retrofit Existing Structure Alternative and no mitigation measures would be required. Temporary impacts during construction are addressed in Section 4.14 — Temporary Impacts During Construction Activities.

Replacement Alternatives N-2 and N-6 (Preferred). The northern alternatives would require placement of footings and columns across the eastern end of YBI. The conceptual development scenario contained in the 1996 Draft Reuse Plan (Figure 4-1 in Appendix A) could be implemented under either Replacement Alternative N-2 or N-6. The number of live/work units and the size of the conference center would be reduced, due to the presence of footings and columns for the northern replacement alternatives; however, the overall concepts could be implemented. Development could occur on 3.15 hectares (7.8 acres) of land, including 1.17 hectares (2.9 acres) beneath the structures, subject to review and approval by Caltrans.

The northern alternatives are consistent with the transportation element of the Reuse Plan because they would not modify YBI on- and off-ramps to change the capacity of existing vehicular access. The ramps are not owned by Caltrans and are not critical to providing a lifeline connection in the project corridor. One eastbound on-ramp is proposed for modification under the replacement alternatives, but would not change access capacity to the island. Therefore, Replacement Alternatives N-2 and N-6 would not conflict with the transportation access assumptions of the 1996 Draft Reuse Plan.

Construction-related impacts are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

Caltrans has initiated consultation with the CCSF concerning the impacts of the northern alternatives on reuse plans. Caltrans will continue to coordinate with CCSF through the final design and construction periods.

Replacement Alternative S-4. Replacement Alternative S-4 would locate the replacement structure to the south of the existing East Span and remove the existing bridge. As a result, the project would open up some additional areas for YBI redevelopment. Approximately 0.8 hectare (2.0 acres) of land that is currently occupied by the existing span could become available for development. This would be a beneficial impact as it relates to CCSF’s redevelopment of YBI. The area suitable for development would be 3.7 hectares (9.1 acres), including 0.6 hectare (1.4 acre) beneath the structures.

As with the northern alternatives, Replacement Alternative S-4 is consistent with the transportation element of the Reuse Plan.

USCG Property Impacts

The development potential of the USCG property would be impacted by the project build alternatives. In April 1998 as part of the BRAC process, the Navy transferred 4.3 hectares (10.6 acres) to the USCG. Of this land, 1.1 hectares (2.7 acres) is within the project area and approximately 0.41 hectares (1 acre) is developable (the remainder is constrained by steep slopes). No specific master plan has been developed for expansion of the existing USCG facility because the USCG has delayed final master plan preparation pending outcome of the TI BRAC process and final design for the East Span Project.

No-Build Alternative. The No-Build Alternative would not affect existing USCG facilities. The No-Build Alternative would not limit future redevelopment beyond the limitations currently imposed by the existing East Span.

Retrofit Existing Structure Alternative. Expansion of existing columns and footings would not conflict with existing USCG facilities or limit future redevelopment beyond the limitations currently imposed by the existing East Span. Temporary construction impacts are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

Replacement Alternatives N-2 and N-6 (Preferred). The northern replacement alternatives would have no permanent impact on USCG usable land area.

Replacement Alternative S-4. Footings and support columns for Replacement Alternative S-4 would use the southeastern portion of YBI and span approximately 1.5 hectares (3.8 acres) of the 17-hectare (41-acre) USCG facility. USCG land under the bridge could be developed, subject to review and approval by Caltrans. Although the USCG does not have a master plan for the YBI facility, Replacement Alternative S-4 would restrict future facility development.

Oakland Touchdown Area

The Oakland Army Base Reuse Authority (OBRA) is in the process of designating land south of Burma Road for light industrial/research and development uses with supporting retail and business services. BCDC amended the San Francisco Bay Plan and the Seaport Plan in January 2001 to delete this area from the "Port Priority Use" designation to permit implementation of OBRA's plan.

The 1998 Draft Final Reuse Plan for the Oakland Army Base designates 5.9 hectares (14.7 acres) of the westernmost portion of the former Army Base on the Oakland Touchdown as the site of a proposed public park. The OBRA is considering reducing the amount of land to 4.9 hectares (12 acres), but has yet to release a revised Reuse Plan. The proposed Gateway Park is a Section 4(f) resource.

The Port and City of Oakland are participants in a planning effort to establish the Gateway Park at the Oakland Touchdown area. (See discussion of Public Parks and Open Space below.) The Port has stated its intention to work with the Oakland Gateway Planning Group to develop design concepts which accommodate the East Span Project, Port activities, public access, and open space in the Oakland Touchdown area.

No-Build Alternative. The No-Build Alternative would not conflict with OBRA's redevelopment plans.

Retrofit Existing Structure. The Retrofit Existing Structure Alternative would not require the use of the former OARB property and would not conflict with OBRA's redevelopment concepts.

Replacement Alternatives N-2 and N-6 (Preferred). The northern alternatives would not use the former OARB property and would not conflict with OBRA's redevelopment concepts.

Replacement Alternative S-4. Replacement Alternative S-4 would conflict with the proposed public park discussed below but would not conflict with OBRA's other redevelopment concepts.

Oakland Touchdown Area — Public Parks and Urban Open Space

With EBRPD as the lead, planning has been initiated with the City of Oakland, the Port of Oakland, EBRPD, ABAG/Bay Trail, OBRA, National Park Service (NPS), and BCDC to create a Gateway Park at the Oakland Touchdown. Decisions about the replacement alternatives are critical to the park planning process.

No-Build Alternative. The No-Build Alternative would not impact EBRPD development of OBRA-designated parkland on the southern border of the Oakland Touchdown area; therefore, no impact to parkland development would occur and no mitigation would be required.

Retrofit Existing Structure. The Retrofit Existing Structure Alternative would not impact EBRPD development of parkland on the southern border of the Oakland Touchdown area; therefore, no impact to development of parkland would occur and no mitigation would be required.

Replacement Alternatives N-2 and N-6 (Preferred). The northern alternatives would not impact EBRPD development of parkland on the southern border of the Oakland Touchdown area; therefore, no impact to development of parkland would occur and no mitigation would be required.

Replacement Alternative S-4. Replacement Alternative S-4 would negatively affect the Gateway Park development at the Oakland Touchdown. This alternative would require approximately 3 hectares (7.4 acres) of the proposed 5.9-hectare (14.7-acre) park for construction of the bridge, thereby reducing its size by one-half and bisecting the land designated for park use by OBRA. The park's reduced size and location would limit its intended function as a regionally significant recreational area and as a gateway to the East Bay. To minimize the impact to the proposed Gateway Park, the land required for Replacement Alternative S-4 could be replaced by acquiring land nearby to contribute toward another smaller park in the area. For further information on the park, see Chapter 6 — Section 4(f) Evaluation.

Impacts to Required Bay Access Sites

As part of the I-880/Cypress Freeway Replacement Project, Caltrans is required by BCDC to provide and maintain a public access bicycle/pedestrian pathway system connecting the Cities of Emeryville and Oakland between Shellmound Street and Nelson Mandela Parkway, through the distribution structure for I-80 to the Oakland Touchdown area. Caltrans is also required to provide two scenic overlooks, a 465-square-meter (5,000-square-foot) outlook on the north side of the Oakland Touchdown area and a 232-square-meter (2,500-square-foot) lookout area on the south side of the Touchdown area. Both overlooks include public amenities such as parking, restrooms, benches, a fish cleaning facility, trash cans, and native landscaping. Caltrans submitted a request to BCDC to amend Permit 11-93 to delay implementation of the access areas until completion of East Span construction. On July 31, 1998, BCDC amended Permit 11-93 to extend the period for construction of the public access areas to December 31, 2006. The permit includes an in-lieu-fee provision that allows Caltrans to pay a sum equal to the costs of the required amenities should construction of some or all of the public access prove infeasible. Payment of the in-lieu fee is subject to BCDC approval. BCDC may disburse the funds to the EBRPD to improve public access where feasible. Each replacement alternative would require ongoing consultation with BCDC to determine the optimum locations of these public access overlooks.

No-Build Alternative. The No-Build Alternative would not interfere with implementation of the public access improvements required under BCDC Permit 11-93. No impact would occur and no mitigation would be required.

Retrofit Existing Structure Alternative. The Retrofit Existing Structure Alternative would not conflict with provision of the public access improvements required under BCDC Permit 11-93.

Replacement Alternatives N-2, N-6 (Preferred), and S-4. Each of the proposed replacement alternatives would have an impact on the public access required under BCDC Permit 11-93. The northern alternatives would preclude construction of the public access overlook required by the BCDC for the northern side of the Oakland Touchdown. Replacement Alternative S-4 would preclude the development of the public access overlook on the south side of the Oakland Touchdown area, bicycle path, access roadway, and parking area required by BCDC Permit 11-93.

Caltrans will consult and coordinate with BCDC to determine necessary public access modifications and/or permit requirements under Permit 11-93. Modifications to the public access requirements could be identified as conditions in a future amendment to Permit 11-93 and/or incorporated into a new permit for a bridge replacement alternative.

4.1.6 Adopted Goals and Policies

The purpose of this section is to evaluate the relationship between the proposed project and existing land use, transportation, and coastal policies which will guide future development in the western and eastern touchdown areas.

Land Use Policies

Treasure Island Draft Reuse Plan (The City and County of San Francisco). The replacement of the East Span would have no impact on CCSF’s program to implement the guiding policies of the 1996 Draft Reuse Plan nor on the CCSF’s program to implement the goals and policies of the CCSF’s Master Plan. The 1996 Draft Reuse Plan and the CCSF’s Master Plan both assume that the East Span will continue to provide an essential link for auto traffic between YBI and the East Bay.

As discussed in Section 4.1.5, Replacement Alternatives N-2 and N-6 are generally compatible with the 1996 Draft Reuse Plan. The 1996 Draft Reuse Plan has not been formally adopted, and it would be subject to environmental and regulatory review, which could alter what is currently envisioned for eastern YBI in the draft plan. The DEIR/DEIS for the reuse plan has not been issued yet.

The goals and policies of the 1996 Draft Reuse Plan also identify the existing bridge and ramps as one of the continuing institutional uses on YBI, as the bridge provides an essential link for auto traffic between YBI and the East Bay. Planned uses on the western side of YBI and on Treasure Island would not be affected by the East Span Project.

City of Oakland (Envision Oakland). The East Span Project is consistent with Oakland’s policies for future development and land uses within the project area. With the exception of one conflict (discussed in Section 4.1.4 — Impacts to Existing Land Use), replacement of the SFOBB East Span would have no impact on the City’s program to implement the goals and policies of the General Plan. Construction of either Replacement Alternative N-2 or N-6 would conflict with the Resource Conservation Area land use designation, which applies to all of the land on the Oakland Touchdown area, north of the existing alignment. The northern alternatives would displace 0.2 hectare (0.5 acre) of the Resource Conservation Area. The City of Oakland has been an active participant in the planning efforts to establish the Gateway Park. As mentioned previously, Replacement Alternative S-4 would negatively impact Gateway Park development. In the City’s comments on the DEIS, Acting Planning Director Leslie Gould noted, "Of the proposal alignments, the City prefers Replacement Alternative N-6 because it would have the fewest impacts on planned land uses."

The SFOBB is an integral part of the existing system that supports Oakland’s vision of the City’s "primacy as a transportation hub connecting the Bay Area with the Pacific Rim and the rest of the United States (Envision Oakland General Plan)."

The Oakland Touchdown area is located immediately adjacent to the City’s seaport area (i.e., Port of Oakland facilities). The seaport area is classified as a showcase district in the City’s General Plan. Showcase districts are dynamic areas that can respond to broad trends and market demands. The policy framework of the plan supports these districts in their continued growth and regional importance. The SFOBB provides an important link between the City’s showcase districts, San Francisco, and the San Francisco Peninsula.

Oakland Policies T4.5, T4.9, and T6.3 support preparation of a Bicycle and Pedestrian Master Plan, the creation of a "gateway" public access area at the east terminus of the East Span, and making the waterfront accessible to bicyclists and pedestrians. The East Span Project includes cooperation by Caltrans with planning efforts to create public access areas in the Oakland Touchdown area that will support implementation of these City policies. These characteristics of the SFOBB project also support the Waterfront Goals of the General Plan, relative to promoting public access to the waterfront.

The "New Bay Bridge," as the SFOBB East Span Project is described in Regional Access: Policies in Action, Chapter 3 of the City’s General Plan, provides opportunities for increased bicycle, pedestrian, and transit access to the bridge. Additionally, the General Plan recommends that new parks and open space at the Oakland Touchdown should be integral components of the project. The replacement alternatives include features, such as the bicycle and pedestrian facilities which are consistent with the City’s policies. All replacement alternatives would accommodate public access through BCDC Permit 11-93 and park development by EBRPD, but Replacement Alternatives N-2 and N-6 substantially more so than Replacement Alternative S-4 because Replacement Alternative S-4 would reduce the size of the proposed park by approximately one-half while Replacement Alternatives N-2 and N-6 would have no impact on the development of the proposed park.

Since the Retrofit Existing Structure Alternative does not provide improved bicycle or pedestrian access, it is not consistent with this Oakland General Plan policy.

Port of Oakland. The SFOBB East Span Project is consistent with the Port and City of Oakland’s plans for an office and commercial development along the shoreline of the Oakland Touchdown area east of the envisioned park. This activity would not be precluded by any of the proposed build alternatives.

U.S. Coast Guard (USCG). The USCG does not currently have a master plan in place for the YBI facility. In general, the USCG plans to maintain its current level of operations at the YBI facility, including 24-hour search and rescue, repair and maintenance of buoys, vessel traffic service, and law enforcement. Replacement Alternatives N-2 and N-6 would not substantially affect current level of operations. Replacement Alternative S-4 would encroach over the USCG facility and would restrict the USCG’s ability to utilize its portion of YBI. The replacement bridge would span approximately 1.5 hectares (3.8 acres) of the 17 hectares (41 acres) of USCG property.

East Bay Regional Park District (EBRPD). As noted in earlier sections, the OBRA’s 1998 Reuse Plan designates 5.9 hectares (14.7 acres) at the westernmost end of the former OARB property for a Public Benefit Conveyance to the EBRPD for a future park. Construction of Replacement Alternatives N-2 and N-6 and the Retrofit Existing Structure Alternative are consistent with the OBRA Reuse Plan and EBRPD’s intention to develop a park after the East Span Project is constructed. Replacement Alternative S-4 would negatively impact the Gateway Park development by taking 3 hectares (7.4 acres) of the proposed park area. (Refer to Chapter 6 — Final Section 4(f) Evaluation for additional information on the proposed Gateway Park and the project alternatives.

Transportation Policies

City of Oakland ­ Envision Oakland. Oakland’s transportation policy includes the following:

Objective T4. Increase use of alternative modes of transportation.

Policy T4.8 - Accommodating Multiple Types of Travel on the Bay Bridge. The City should encourage the design and engineering for the new Bay Bridge to accommodate multiple means of access and travel by automobiles, trucks, transit, bicycles, pedestrians, and future mass transit.

Each of the East Span Project replacement alternatives would accommodate multi-modal travel on the bridge. High-occupancy vehicle (HOV) bypass ramps would remain in operation at both the west and east bridge approaches to encourage carpools, vanpools, and bus transit use. Provision for future mass transit would be accommodated by continuation of Alameda-Contra Costa Transit District (AC Transit) bus service and by design of the replacement structures to accommodate loading for future light rail transit vehicles. Replacement alternative designs also include a bicycle/pedestrian path. The proposed project is consistent with this policy.

Policy T4.8 - "Gateway" Public Access Area. The City, in concert with the EBRPD, Port of Oakland, Oakland Base Reuse Authority, and BCDC, should support development of a significant new "gateway" public park area at the terminus of the SFOBB East Span that can be reached by auto, bicycle, or walking.

The East Span Project includes coordination with the agencies concerned with future uses of land in the Oakland Touchdown area. Collaborative planning efforts involving the City of Oakland, Port of Oakland, EBRPD, BCDC, NPS, and the Army are in progress.

City and County of San Francisco Master Plan. The CCSF’s transportation policy includes the following:

Objective 1.

Policy 1. Involve citizens in planning and developing transportation facilities and services, and in further defining objectives and policies as they relate to district plans and specific projects.

The East Span Project is consistent with this policy as it has provided many opportunities for public involvement in the process. (See Appendix E for a summary of public involvement activities.)

Objective 4.

Policy 2. Where significant transit service is provided by buses, bridges and freeways should have exclusive bus lanes.

Efficient bus operations as part of the East Span Project alternatives are facilitated by provision of bus/carpool (HOV) bypass lanes at the west and east bridge approaches. Provision of exclusive bus lanes has been considered as part of the East Span Project. It was determined that dedicated facilities would not provide any benefits. (See Section 2.5.)

Objective 5.

Policy 3. The existing vehicular capacity of the bridges, highways and freeways should not be increased and should be reduced where possible.

The East Span Project is consistent with this policy as it does not increase capacity.

Objective 8.

Policy 4. Accommodate bicycles on regional transit facilities and important regional transportation links.

The East Span Project replacement alternatives include designs for a bicycle/pedestrian path. The replacement alternatives are consistent with this policy.

Association of Bay Area Governments ­ The Bay Trail. ABAG’s plans for trails include the following:

Transportation Access Policies.

The East Span Project would be consistent with these policies because the replacement alternatives would provide the first link of a transbay crossing by providing a path to YBI. (The feasibility of a West Span path is under review by the MTC and Caltrans.) A path on the East Span would be an important connection to Bay Trails on both sides of the Bay. The East Span Project would improve access to the bridge and would enhance the safety of the bridge itself. The bicycle/pedestrian path is to be funded as outlined in Section 188 of the California Streets and Highways Code (CSHC).

San Francisco Bay Plan (Bay Conservation and Development Commission) Policies.

Land Use. BCDC requires that every project provide the maximum feasible public access to the Bay consistent with the project. In planning meetings for the conceptual Gateway Park at the Oakland Touchdown area, BCDC concurred that it would consider combining the requirements for public access specified in Permit 11-93 with any additional public access requirements for the East Span Project. (Note: Section 60604.5 of the Streets and Highways Code states, "Notwithstanding any other provision of law, local and state permitting authorities shall not impose any requirement that a bicycle, pedestrian, or mass transit facility be constructed on the San Francisco-Oakland Bay Bridge as a condition for issuing any permit, granting any easement, or granting any other form of approval needed, for the construction of a new bridge." As a result of this law, BCDC cannot require a bicycle or pedestrian facility on the bridge as a permit condition.)

The East Span Project would be consistent with BCDC’s public access policy as Caltrans would provide bicycle, pedestrian, and vehicular access to the Oakland Touchdown area as part of both the East Span Project and BCDC’s previous conditions of approval for the I-880 and I-80 projects (see the Permit 11-93 discussion in Section 3.1.3 — Adopted Goals and Policies for further details). Public access to the Bay is required as part of the I-880 and I-80 projects. If the public access improvements, including the overlooks and bikeway alignments prove infeasible due to replacement of the bridge, the permit conditions allow Caltrans to pay an in-lieu fee to construct the improvements subject to BCDC approval. BCDC may disburse the funds to the EBRPD or another entity to improve public access where feasible.

The proposed project is consistent with the BCDC’s policies for future development as contained in the San Francisco Bay Plan and the Seaport Plan; the replacement of the East Span would have no impact on the BCDC’s program to promote its policies guiding land use and development around the Bay. The Bay Plan strongly encourages that new transportation facilities be designed to encourage use of mass transit. The proposed project is consistent with this policy, as the proposed alternatives would maintain the HOV bypass lanes at the toll plaza and west approach that presently take buses and carpools around congestion points. The Bay Plan also strongly encourages development and use of public parks. The configuration of overlooks required as part of the I-880 and I-80 projects would be affected by the East Span Project. Given the intent of EBRPD and other parties to provide a much larger area for public access and amenities south of the bridge, public access requirements for parks and overlooks are expected to be fulfilled with any replacement alternative, though with a lesser quality park configuration under Replacement Alternative S-4. EBRPD plans for the Gateway Park are independent of the East Span Project.

Transportation. The BCDC Bay Plan includes the following:

Policy 4. If a route must be located across a waterway, the following provisions should apply:

a. The crossing should be placed on a bridge or in a tunnel, not on solid fill.

c. Toll plazas, service yards, or other ancillary features should not be located on new fill.

The East Span Project is consistent with BCDC policy "a". All alternatives propose a bridge crossing. Concerning policy "b", the height of all alternatives under consideration has been set in consultation with the USCG to provide adequate navigational clearance. Project alternatives would not require new fill for ancillary facilities. The project alternatives are, therefore, consistent with policy "c". Although the project does not propose a new route over the Bay, project alternatives are consistent with policy "d" in that consideration is being given to accommodation of structural loading requirements for future light rail transit.

Dredging and Fill. Bay Plan Dredging Policy 2 establishes a preferential hierarchy for disposing of dredged material. This hierarchy is intended to minimize impacts to the Bay from dredge disposal activities. The policy states that dredged material should be disposed of by:

• Placement as fill in approved locations;
• Ocean disposal;
• Dry land disposal; and
• In-Bay disposal at designated locations.

Dredging required for the project would result from construction activities (see Section 4.14.10 — Construction Excavation and Dredging). Caltrans has initiated consultation with BCDC and other regulatory agencies through the Dredged Material Management Office (DMMO) concerning disposal of dredged materials (see correspondence in Appendix G). Dredged material would be disposed of at locations approved by the DMMO and subject to BCDC review for policy consistency.

Section 66605 of the McAteer-Petris Act (discussed in Section 3.1 — Community Setting) and the Bay Plan regulate Bay fill, requiring that fill be minimized and permitted only if it meets certain conditions. Under Section 66605, bridges are considered to be water-oriented uses for which fill can be placed in the Bay. (Refer to Section 4.9.1 — Placement of Fill in the San Francisco Bay for a discussion of Bay fill quantities.) Permanent Bay fill associated with the build alternatives include bridge piles, pile caps, piers, and decks, and engineered fill for the westbound roadway and Caltrans' maintenance road at the Oakland Touchdown area. Temporary Bay fill associated with the build alternatives include trestles, falsework, cofferdams, barge mooring facilities, and other construction facilities.

Visual. Bay Plan policies related to the appearance and design of bridge structures and the visual prominence of bridge towers are advisory only. Policies relating to maximizing views to the Bay from bridges are enforceable. The Retrofit Existing Structure Alternative is generally consistent with these policies because it would not change existing railing heights or add substantial new superstructure that would decrease motorists’ views. Modifications to the substructure including addition of two bridge columns and expansion of existing columns would not change the basic visual form of the existing structure.

The replacement alternatives are consistent with the Bay Plan’s visual policies. Bay Plan policies concerning views to and from the bridge and tower type and design were incorporated into design recommendations developed by the Metropolitan Transportation Commission's (MTC's) Bay Bridge Design Task Force (Task Force) and the Engineering and Design Advisory Panel (see Appendix E).

Construction of the build alternatives (including the Retrofit Existing Structure Alternative) would require a permit from BCDC pursuant to the McAteer-Petris Act and a concurrence from BCDC that the project is consistent with the Commission’s federally approved Coastal Zone Management Program (CZMP). Both the required development permit and the concurrence must establish that construction of the replacement alternatives is consistent with the McAteer-Petris Act, the San Francisco Bay Plan (including the "Park Priority Use" designation at YBI), and the Seaport Plan.

Caltrans has initiated consultation with BCDC concerning consistency of the East Span Project with the Commission’s CZMP. In a letter dated February 4, 2000, BCDC provided a preliminary concurrence for the East Span Project. (Refer to Appendix G: Agency Consultation Letters.)

After the Record of Decision has been approved, the FEIS and detailed engineering will be provided to BCDC during final project design for its use in the federal consistency concurrence and Bay Plan permit process.

4.2 TRANSPORTATION

Each of the proposed alternatives would retain five eastbound and five westbound traffic lanes on the East Span. Replacement alternatives would require roadway modifications on YBI and the Oakland Touchdown area (as summarized below), but none of the alternatives would create long-term impacts to local traffic, transit, and maritime traffic. Construction-related impacts are discussed in Section 4.14 — Temporary Impacts During Construction Activities.

4.2.1 Vehicular Circulation and Access

For each alternative, changes in vehicular traffic circulation, operations, and access are identified and design considerations are described that would be incorporated into the alternatives.

SFOBB Traffic Operations

Traffic operations under the No-Build Alternative and the Retrofit Existing Structure Alternative would remain the same as under existing conditions. Each of the East Span replacement alternatives may improve traffic operations on the SFOBB: the addition of 3-meter (10-foot) shoulders on both sides of the roadway would provide refuge for disabled vehicles. This may reduce non-recurrent congestion caused by minor accidents or stalls that block one or more lanes of traffic. However, the extent of non-recurrent congestion caused by major incidents is unlikely to be affected by the addition of shoulders. The addition of shoulders would also reduce the number of lane closures for maintenance.

During traffic incidents, all of the proposed replacement alternatives for the East Span Project may experience traffic operational impacts in the opposite travel direction from the incident as a result of rubbernecking. When an incident occurs on a typical freeway segment, secondary congestion frequently occurs in the opposite direction of travel as a result of drivers slowing to view the incident. When an incident occurs on either the upper or lower deck of the existing SFOBB, there is currently no impact to traffic headed in the opposite direction because drivers are unable to see opposing traffic or incidents. The proposed replacement structures would place eastbound and westbound traffic at the same level and 15 meters (50 feet) apart, creating opportunities for drivers to see incidents on the opposite structure, which may cause delays in the non-incident travel direction.

Yerba Buena Island

There would be no long-term impacts to traffic circulation, access, or transit operations on YBI from the No-Build Alternative, Retrofit Existing Structure Alternative, or the replacement alternatives. The replacement alternatives would, however, create long-term changes in the alignment of certain YBI roadways as described below. These roadway modifications would be required for each replacement alternative. No loss of access would result under the replacement alternatives. Neither the No-Build nor the Retrofit Existing Structure Alternative would require long-term roadway modifications.

Required roadway modifications as a result of the Preferred Alternative are described in detail in Section 2.6.2 — Bridge Replacement Alternatives and summarized below:

• Macalla Road would be lowered approximately 1 meter (3 feet) and realigned to avoid bridge columns and connect with a modified Southgate Road. All existing access to Macalla Road would be maintained;

• Southgate Road would be realigned both horizontally (13 meters [43 feet] east) and vertically (up to 3 meters [10 feet]). All existing access would be maintained;

• The USCG Road would be realigned 20 meters (66 feet) south to avoid the columns of the new bridge. Construction would include a new gate and guard shack for the USCG facility; and

• A portion of the access road leading to Building 262 would be permanently realigned approximately 15 meters (49 feet) to the south. The realigned portion would become a two-lane roadway that would conform to the existing single-lane dirt road approximately 115 meters (377 feet) from the eastern end of YBI.

The vertical and horizontal changes to the roadways would be slightly different for each replacement alternative, depending on the bridge alignment.

Oakland Touchdown Area

No-Build Alternative, Retrofit Existing Structure Alternative, Replacement Alternatives N-2 and N-6 (Preferred). The No-Build Alternative, Retrofit Existing Structure Alternative, and Replacement Alternatives N-2 and N-6 would have no long-term impacts to traffic circulation, access, or transit. Under the northern replacement alternatives, the existing Caltrans maintenance road would be realigned, but there would be no loss of access.

Replacement Alternative S-4. Replacement Alternative S-4 would not affect existing transit service in the Oakland Touchdown area, but would require modification of existing access patterns.

Under Replacement Alternative S-4, the existing Caltrans maintenance road would need to be realigned (see Figures 2-11.4 and 2-11.5 in Appendix A). The southern shoreline east of Replacement Alternative S-4 would continue to be accessed by Burma Road, which would be truncated at existing Terminal Seven. The portion of Burma Road that would be eliminated would not affect traffic circulation or access to any buildings in the area. No loss of access would occur to Caltrans maintenance buildings because access would be configured to the south using the realigned maintenance road. The vertical clearance between the new bridge approach structure and the EBMUD service road would be insufficient to allow large delivery truck access to the EBMUD dechlorination facility. Relocation of the service road, the facility, or both would be required (see Section 4.1.4 — Impacts to Existing Land Use for further discussion).

Local access roadway reconfigurations would be part of the construction of Replacement Alternative S-4. Realigned access roadways would serve existing facilities and any future park development, with the exception of the dechlorination facility. Relocation of the dechlorination facility is discussed in Section 4.1.4 — Impacts to Existing Land Use. No other impacts due to change in access would result; therefore, no mitigation is proposed.

4.2.2 Non-Motorized Traffic: Bicycles and Pedestrians

Pedestrian and non-motorized traffic are currently prohibited on the existing East Span and no dedicated, signed bicycle/pedestrian paths currently exist within the project area. Project alternatives have been assessed for the potential to accommodate planned and proposed pathway connections, and the replacement alternatives each incorporate a bicycle/pedestrian path.

Citizen participation in planning for the bicycle/pedestrian path on the East Span has been facilitated by the MTC and Caltrans through the Bay Bridge Bicycle/Pedestrian Advisory Committee (BPAC).

Yerba Buena Island

Project alternatives have no permanent impacts to bicycle and pedestrian circulation on YBI. The 1996 Draft Reuse Plan proposes bicycle and pedestrian modes as the primary modes of transportation on YBI. There are currently no signed bicycle paths or lanes on YBI and the Navy and the CCSF have no plan in place for the creation of bicycle/pedestrian facilities on the island. Bicycle and pedestrian use of public street rights-of-way on YBI would be possible under any East Span Project alternative. The bicycle/pedestrian path proposed for the Preferred Alternative (Replacement Alternative N-6) and Replacement Alternatives N-2 and S-4 would terminate on the eastern side of YBI. In the final design phase for a replacement alternative, Caltrans would work with the Navy and/or the CCSF to design appropriate path connections to the local roadway network. Caltrans would consult with the Navy and/or other property owners on YBI about their interest in having directional signage installed for path users on the bridge. If consultation results in agreement on the nature and placement of the signs, Caltrans would install the signage. To the extent the Navy and CCSF believe the SFOBB bicycle/pedestrian path would create excessive demand on Navy/CCSF facilities on YBI, Caltrans would limit access to YBI at the request of the Navy and/or the CCSF. Should the Navy or the CCSF desire YBI access to be specifically directed, limited, or prohibited, Caltrans would work with these agencies to design signage or barriers. Caltrans does not have responsibility or authority for areas of YBI and TI once path users leave the path on the East Span.

Caltrans and MTC are currently preparing a feasibility study for a possible bicycle/pedestrian/maintenance path from San Francisco across the West Span and a connection around YBI to a path on the replacement East Span. The preliminary design in this study locates the potential West Span path at the upper deck level outward of the existing stiffening trusses on both sides of the West Span. The pathway would descend into San Francisco on elevated structures west of the current San Francisco anchorage and terminate near the intersection of Harrison and Fremont Streets. East of the YBI anchorage, the path would continue on elevated structures which would connect to an at-grade path along the south side of YBI, generally along the existing Treasure Island Road, that would then connect to the East Span path. Any future pathway on the West Span and on YBI would be a separate project. The East Span path could accommodate connections to a possible path on the West Span.

No-Build and Retrofit Existing Structure Alternatives. The No-Build and Retrofit Existing Structure Alternatives would have no impacts to bicycle and pedestrian circulation in the Oakland Touchdown area.

Replacement Alternatives. The replacement alternatives, including the Preferred Alternative (Replacement Alternative N-6), would create no negative impacts to bicycle and pedestrian circulation in the Oakland Touchdown area. Access to and from the replacement alternatives would be from the south side of the eastbound structure. Each of the replacement alternatives would provide bicycle/pedestrian access to the bridge and would provide sufficient vertical clearance where necessary to permit a bicycle and rider to travel under bridge structures. The Bay Trail would connect with the East Span structure from West Oakland along a bikeway adjacent to I-80 to be provided by Caltrans under the requirements of BCDC Permit 11-93. This Oakland-to-Emeryville segment of the Bay Trail will be funded by Caltrans as part of the I/880 Cypress Freeway Replacement Project. Implementation of this Bay Trail segment will be coordinated with the East Span Project and Gateway Park plans.

East Span Bicycle/Pedestrian Access

Proposed alternatives have been evaluated for their potential to provide bicycle and pedestrian access to and on the East Span. Criteria used to assess project impacts are:

• Ability to incorporate a bicycle and pedestrian path on the East Span;
• Suitability of profile grades; and
• Connectivity to bicycle and pedestrian access at either the Oakland Touchdown area or YBI.

No-Build and the Retrofit Existing Structure Alternatives.

Path Accommodation and Placement. The No-Build and the Retrofit Existing Structure Alternatives do not incorporate a new bicycle and pedestrian path. The existing cross section of the bridge has five 3.5-meter (11.7-foot) travel lanes with no roadway shoulders, limiting the ability to restripe the bridge deck to accommodate a path on the bridge. It may be possible to add a bicycle/pedestrian path to the existing bridge in the future under the No-Build or Retrofit Existing Structure Alternatives; however, MTC has provided funding only for a path on a replacement alternative.

Replacement Alternatives N-2, N-6 (Preferred), and S-4.

Path Accommodation. A bicycle and pedestrian path has been incorporated into each replacement alternative (see Figure 2-8 in Appendix A). A path would be constructed on the south side of the eastbound structure for each replacement alternative. The path would be 4.7 meters (15.5 feet) wide and 0.3 meter (1 foot) higher than the adjacent travel lanes and would include viewing areas, referred to as belvederes. The five belvederes on the skyway would be approximately 12 meters (39 feet) long by 1.2 meters (4 feet) deep. Caltrans is still investigating whether to include one or two belvederes on the main span; they would be 20 meters (66 feet) long by 1.2 meters (4 feet) deep. This configuration was developed with input from the BPAC and was approved by the MTC. Provision of bicycle/pedestrian access on the East Span would be a beneficial impact.

Consistency with Local Plans and Policies

Each of the East Span replacement alternatives, including the Preferred Alternative, would provide a bicycle and pedestrian path between YBI and the Oakland Touchdown area. Provision of the path would be consistent with the following local plans:

• City and County of San Francisco, Naval Station Treasure Island Draft Reuse Plan;
• San Francisco Bay Conservation and Development Commission, Bay Plan;
• City of Oakland, Pedestrian and Bicycle Master Plan; and
• Association of Bay Area Governments, Bay Trail Plan.

Impacts to SFOBB Bicycle Shuttle Service

All East Span Project alternatives could accommodate the existing Caltrans bicycle shuttle service.

4.2.3 Parking

For each alternative, changes in long-term parking supply resulting from project alternatives have been identified. It should be noted that Caltrans' temporary construction easement (TCE) includes the majority of the Parade Grounds, where YBI parking is available. A small portion of the Parade Grounds is owned by Caltrans. The TCE shall terminate when Caltrans determines that it no longer is required , at which time the property will revert to the federal government.

Yerba Buena Island

No-Build Alternative. The No-Build Alternative would not modify the number of parking spaces on YBI.

Retrofit Existing Structure. Strengthening of existing Column YB3 under the Retrofit Existing Structure Alternative would eliminate approximately four informal parking spaces in the paved area east of Quarters 1. Given the large undeveloped area available for parking, the loss of four parking spaces at the eastern end of this area would not contribute to unmet parking demand and would not create an impact. No mitigation would be necessary for this minor change in parking supply.

Replacement Alternatives. Each of the East Span Replacement Alternatives, including the Preferred Alternative, would eliminate between 6 and 8 informal parking spaces in the paved area east of Quarters 1. Given the large undeveloped area available for parking, the loss of this small number of parking spaces would not contribute to unmet parking demand and would not create an impact. No mitigation would be necessary for this minor change in parking supply.

Oakland Touchdown Area

There would be no long-term loss of parking spaces under any of the project alternatives. The project would add day-use parking as part of public access. There would be a new parking lot near the entrance to the bicycle/pedestrian path on the bridge. The parking lot would be temporary to avoid conflicts with plans for the Gateway Park and could eventually be incorporated into the park design. The size of the lot is undetermined at this time, but would, at a minimum, satisfy the parking requirements of BCDC Permit 11-93 for six parking spaces.

4.2.4 Marine Traffic

The potential for ship collisions with the East Span alternatives has been evaluated. Impacts to the structures from vessel types likely to use the waters under the bridge are presented below.

Methodology

Information regarding type, size, and frequency of vessels that use the shipping channel east of YBI was collected to determine vessels likely to pass under the East Span in open water. The largest vessels currently using the main navigation opening are fuel barges traveling to and from the oil refinery at Point Richmond.

American Association of State Highway and Transportation Officials (AASHTO) specifications were used to estimate impact loads on towers and columns. Head-on and side-impact collisions were considered. To evaluate worst-case impacts, it was assumed that cruise ships could use the east channel under potential development scenarios for TI. The vessel’s speed, mass, and crushing of its hull were considered in developing impact loads. Cruise ships, being larger than existing barges using the eastern navigation channel, would generate the largest impact loads.

No-Build Alternative

The No-Build Alternative would not modify the existing East Span and would not change navigation patterns through the main navigation opening. No modifications to the bridge are proposed under this alternative; therefore, no modifications would be constructed to minimize impacts of future ship collisions. Should a collision occur, existing fenders would protect the existing bridge. Existing deteriorated fenders are being repaired, and these fender systems would also be repaired as required following vessel collisions.

Retrofit Existing Structure Alternative

The Retrofit Existing Structure Alternative would strengthen existing columns in the main navigation opening, shorten spans, increase the ability of the structure to withstand impact from a maximum-design cruise ship at the main span columns and impacts of barges at the shorter span columns. More columns would increase the likelihood of a collision between a vessel and a column. The additional columns would also narrow the existing main navigation opening. The alternative would maintain a width of at least 147 meters (481 feet) between columns in the main navigation opening, and a vertical clearance of 42 meters (138 feet) over mean high water. The resulting channel width, while slightly less than the 152 meters (500 feet) recommended by the USCG, would be adequate for navigation. Following construction of Columns E2A and E2B in the existing main navigation opening, column protection, such as fenders, would be needed at least in the three new main navigation openings. The USCG is evaluating whether or not column protection would be needed in other navigation openings. Column protection would be provided where identified as necessary by the USCG.

Replacement Alternatives N-2, N-6 (Preferred), and S-4

As part of the bridge design, protective fenders are proposed at the main tower and skyway columns to provide sufficient standoff to prevent vessels from hitting columns and reduce pile cap damage on impact. The fenders could be either pile-supported or pile cap-mounted. One possible fender system would have a timber-rubbing face and remain elastic up to a particular level of impact energy. Beyond this level, it absorbs energy by damage to the concrete and timber, but is designed to be easily repaired. The system also provides a wearing surface on the column for minor collisions and bumps from merchant and recreational vessels.

All skyway foundations would be able to withstand the impact of a light drifting barge, and skyway columns would be able to withstand the maximum-design barge impact. The main towers and skyway column foundations would be capable of sustaining impacts for the maximum-design cruise ship.

No potential for significant damage to replacement structures has been identified, due to design of columns and fender systems, and no mitigation is required.

Each of the replacement alternatives would narrow the existing main navigation opening approximately 57 meters (187 feet). The replacement alternatives would have a navigation opening width of 348 meters (1,142 feet) and a vertical clearance of 43 meters (140 feet) over mean high water, and the resulting horizontal and vertical clearance would conform to USCG recommendations. The project would install all applicable navigation aids, such as fenders and lights.

4.2.5 Air Traffic

The No-Build and Retrofit Existing Structure Alternatives would not change the location or height of towers and would not require changes to obstruction markings or lighting to alert aircraft to the presence of the existing East Span.

The replacement alternatives, including the Preferred Alternative, would change existing obstruction markings and lighting. Federal Aviation Administration (FAA) Form 7460-1, "Notice of Proposed Construction or Alteration," would be filed with the FAA. The form would disclose the location and height of a cable-supported tower. The main span tower of the replacement alternatives would be higher than 150 meters (500 feet) above mean sea level and would require warning lights. Warning lights are required because the tower would exceed 61 meters (200 feet), which is FAA’s maximum height for which warning lights are not required.

4.3 VISUAL IMPACT ANALYSIS

The purpose of the visual impact analysis is to evaluate the large-scale visual impacts of the project on the Bay Area.

The focus of the visual impact assessment is on the visual impacts of the Retrofit Existing Structure Alternative and design variations of the replacement alternatives (skyway and main span) and alignments of replacement alternatives (Replacement Alternatives N-2, N-6, and S-4) in terms of visual obstruction, dominance within the viewshed, and design quality in terms of vividness, intactness, and unity. These issues are also considered with respect to the types of viewers that would be affected by the project (residents, office workers, motorists, pedestrians, bicyclists, and recreational users).

The visual simulation figures (4-4 through 4-17c) in Appendix A include the Retrofit Existing Structure Alternative and Replacement Alternatives N-6 and S-4. Replacement Alternatives N-6 and S-4 were chosen because they demonstrate most clearly the differences between a northern and southern alignment. Replacement Alternative N-2 was not used in the photo simulations because it is located between the two other alternatives and would not enhance the representation of differences between a northern and southern alignment.

The following sections describe the visual impacts of the various project alternatives on each of the landscape units which make up the project area (Section 4.3.1), as well as the changes in visual quality that would be experienced from the 20 representative viewpoints around the Bay Area (Section 4.3.2). The changes in visual quality for motorists traveling on the East Span are also discussed (Section 4.3.3). Impacts and mitigation for tree removal and slope disturbance are summarized in Section 4.3.4.

Various bridge types other than cable-stayed, self-anchored suspension (preferred design variation), and skyway designs are not discussed in this section. An earlier process was established to evaluate the merits of these other bridge design types. The process began with meetings of the MTC Bay Bridge Design Task Force. The Task Force initiated an open request for ideas about the design of the main span of the East Span and held numerous public meetings. The Task Force also received an evaluation of various designs by a distinguished panel of engineering and architectural experts (the Engineering and Design Advisory Panel) and elected officials. (See Appendix E — Consultation and Coordination for more details.)

4.3.1 Visual Impacts Resulting in Changes Within Landscape Units

Landscape units are geographically distinct portions of the study area which have a particular visual character. The change to each of the five landscape units described in Section 3.3.2 — Existing Landscape Units and Visual Image Types was assessed for each of the four build alternatives and a number of design variations. The impact on landscape units and visual image types is evaluated for the period when the bridge is in full operation. Each landscape unit would be affected differently according to the combination of these alternative/design variations.

Yerba Buena Island

Retrofit Existing Structure Alternative. The retrofit alternative would not require alteration of visual features on the island. Operations would be identical to what exists today. All visual image types within this landscape unit would remain intact. Adding substantial structural members on the outside of the cantilever superstructure would add clutter and mass to existing bridge.

Skyway/Main Span Design Variations. Following construction and dismantling of the existing bridge, the YBI landscape unit would appear altered by the removal of portions of woodlands to the north and south of the span. The removal of vegetation would be a substantial alteration of this landscape unit and, depending on the size and species of the replacement planting, would require approximately 10 to 20 years to reestablish itself to its current density. It is probable, depending on the amount of clearing required, that residential structures currently obscured by the vegetation would become visible. Mitigation is discussed in Section 4.3.4 — Impacts Due to the Removal of Vegetation and Slope Disturbance.

The slope to the south of the East Span is extremely steep and, though the steepness of the slope would restrict the amount of construction activity which could take place on it, some access would be necessary to construct temporary and permanent columns on and near the slope. The appearance of this part of the slope may be permanently altered after construction, since the extreme angle of the slope and the characteristics of the underlying geology may not permit the slope to be returned to its original grade.

In addition, the footprint of the bridge itself would be altered because the single-deck roadway design would be more than three times the width of the existing span and require approximately 25-30 columns which would affect views to and from the island.

Replacement Alternative S-4 would reduce the size of the USCG facilities, although the structures that could be removed are not currently visible from the existing span. Similarly, Replacement Alternatives N-6 (Preferred) and N-2 would reduce the image type represented by removing Buildings 30, 40, 75, and 270. These structures are not currently visible from the existing span.

Main Span

Retrofit Existing Structure Alternative. Following the seismic strengthening measures, the landscape unit would reflect a slight increase in view blockage as a result of the introduction of two new columns, encasing other columns, and the installation of cross pieces. This would not be considered a substantial visual impact. The Bay would remain the predominant visual image type within this landscape unit.

Skyway Design Variation. Following the construction and dismantling period, this landscape unit would appear much different. The bridge deck would exhibit a much thinner profile than the existing structure because the cantilever element would not be present. In addition, the bridge would be a single-deck rather than a double-deck roadway. The steel cross beams that extend from the upper to lower deck on the existing structure would no longer be present. The skyway design variation profile would consist of a simple concrete sidewall along either side of the deck, reading like a ribbon from points north and south. The predominant visual image type within this landscape unit would be the Bay.

Main Span Bridge Design Variation. Following the construction and dismantling period, the landscape unit would be dominated by a much taller and different tower element. The contrast between the existing cantilever and truss elements and the proposed single-tower element would be dramatic. The bridge would also be modified through the removal of the double-deck roadway. The single-deck side-by-side roadway would produce a much thinner profile, and the image of the bridge would be sleeker and lighter, because there would no longer be steel beams connecting the upper and lower decks. The predominant visual image type would remain the Bay.

Incline Section

Retrofit Existing Structure Alternative. The retrofit alternative would produce the least amount of change from the existing span. The span would continue to have two bridge decks connected by steel beams. The predominant visual image type of the incline section would remain the Bay. No change in the SFOBB’s alignment would occur, and the bridge would appear visually much as it does today.

Skyway/Main Span Bridge Design Variations. Both the skyway and main span design variations would provide a skyway deck along this portion of the span. The greatest change to this landscape unit involves the replacement of the existing double-deck structure with side-by-side single decks. This change would cause the bridge to be more than double in width, while the height of the deck area would be reduced as a result of the reduced height of the bridge rail and the absence of the upper deck.

Replacement Alternative S-4 would offer the greatest change in viewshed as it follows a more southerly alignment, while Replacement Alternatives N-6 (Preferred) and N-2 remain closer to the SFOBB’s existing alignment along this section of the bridge.

Oakland Touchdown

Retrofit Existing Structure Alternative. The retrofit alternative would produce the least amount of change from the existing span. The visual image types currently present at the touchdown area would not be altered with the implementation of the retrofit alternative. The alignment of the East Span would not change and additional right of way would not be required for its construction. The predominant visual image types would remain marsh and estuary areas and light industrial.

Skyway/Main Span Bridge Design Variations. Replacement Alternatives N-6 (Preferred) and N-2 would require construction within a portion of the area to the north of the existing span designated for resource conservation by the City of Oakland. Replacement Alternative S-4 would require construction within undeveloped and light industrial land to the south of the existing span. The result of this change in the SFOBB’s existing alignment would be a reduction in the visual image types (marsh, estuary, and light industrial) associated with the land taken by the replacement alternatives. Replacement Alternatives N-2 and N-6 (Preferred) may involve adding fill along the north side of the Oakland Touchdown to support bridge approach structures. Addition of fill would change the appearance of this portion of the touchdown.

The bridge itself would produce a much narrower profile and would be a lighter, more streamlined structure. The steel cross beams that currently extend between decks would not be present, and the single decks would be placed side by side rather than stacked one on top of another. The structure would be similar to what exists today as the bridge at this point is rejoining the SFOBB’s existing alignment as it approaches the toll plaza.

SFOBB Toll Plaza

The toll plaza area would not undergo substantial change as a result of the project. The proposed replacement alternatives, including the Preferred Alternative, would rejoin the existing roadway at the toll plaza. The location of the toll booths would not change, and the realignment of the roadway to the north or south would not substantially affect the existing visual appearance of this landscape unit.

4.3.2 Impacts on Views from the Bridge

The following section describes the visual changes that motorists traveling on the SFOBB East Span would experience under the retrofit and replacement alternatives. To aid in this evaluation, an animation of the motorists’ views was created for the replacement alternative’s main span bridge design variations. Still pictures of key views from this animation are presented in Figures 4-2 to 4-3b in Appendix A. The complete set of animation is provided on a CD-ROM included in the Visual Impact Assessment Report which can be reviewed at locations identified in the Preface and on the worldwide web at www.dot.ca.gov/dist4.

Retrofit Existing Structure Alternative

The retrofit alternative would only slightly change motorists’ views from the existing East Span. The current double-deck structure would be maintained, including its solid steel sidewalls that block some motorists’ views of the Bay. Steel crossbeams that extend from the upper to the lower deck would be modified to permit large displacements at specified joints. As a result, views would continue to be restricted, especially in the eastbound direction where the presence of the westbound deck overhead results in a further obstruction to the viewshed. Adding substantial structural members on the outside of the cantilever superstructure would add clutter and mass to the existing bridge.

Skyway Design Variation

The skyway design variation would result in substantial changes to the motorists’ view, because it would create side-by-side roadway decks with concrete side barriers and railings designed to facilitate views from the structure unlike the existing structure that has steel cross beams that extend from the upper to the lower structure. Because the skyway design variation would not include a main span tower, views would remain unobstructed throughout the length of the East Span.

With Replacement Alternatives N-6 (Preferred) and S-4, views toward the skyline of San Francisco would be expanded for westbound travelers, while Replacement Alternative N-2 would produce views similar to the existing span. Eastbound travelers would experience expansive views toward the Port of Oakland and toward the hills above the communities of Oakland, Berkeley, and Alameda, although visibility to the south may be compromised by the presence of a 4.7-meter (15.5-foot) wide bicycle/pedestrian lane and railings.

Although views from the East Span with the skyway design variation would be greatly expanded, three design issues would have an impact upon the extent of views from the structure. First, the roadways would be placed side by side. The impact of side-by-side roadways would be that viewers would have a five-lane roadway in the foreground of their view to the north (when traveling in the eastbound direction) or south (when traveling in the westbound direction). Second, the addition of a 3-meter (10-foot) shoulder on each side of the roadway further expands the structure in the motorists’ foreground view. Finally, the creation of a 4.7-meter (15.5-foot) wide bicycle/pedestrian path on the south side of the eastbound bridge deck would affect views southward from the East Span. The bicycle and pedestrian lane would be raised 0.3 meter (1 foot) above the flow of auto traffic, further restricting views to the south.

When comparing replacement alternatives, Replacement Alternatives N-6 (Preferred) and S-4 would expand westbound views toward San Francisco by allowing views around YBI, because of their northerly and southerly locations, respectively, in comparison with the existing East Span. Replacement Alternative N-2 would expand views to a lesser degree because it closely follows the alignment of the existing East Span.

Main Span Design Variations

The main span design variations would also expand views from the East Span because, as with the skyway design variation, the East Span would be constructed with side-by-side roadways, concrete side barriers, and railings designed to facilitate views from the structure. The main span tower and cables would somewhat obstruct views as vehicles pass through the main span section. However, overall views would increase greatly when compared with the existing structure. In addition, views of the towers and cables while driving on the incline would increase the vividness of the view from the incline.

As with the skyway design variation, Replacement Alternative N-6 (Preferred) and Replacement Alternative S-4 would produce expanded views toward the skyline of San Francisco for westbound travelers, while Replacement Alternative N-2 would produce an effect similar to the existing span. Eastbound travelers would experience expansive views toward the Port of Oakland and toward the hills above the communities of Oakland, Berkeley, and Alameda, although views to the south may be compromised by the presence of a 4.7-meter (15.5-foot) wide bicycle/pedestrian lane and railings.

The design issues noted above for the skyway design variation would have a similar impact on views from the main span tower. The creation of side-by-side single decks, the addition of 3-meter (10-foot) shoulders, and the construction of a 4.7-meter (15.5-foot) bicycle/pedestrian path would restrict views from the East Span to the north and south. Figures 4-2, 4-3a, and 4-3b in Appendix A depict a motorist’s view while driving on the main span variation.

When comparing replacement alternatives, Replacement Alternatives N-6 (Preferred) and S-4 would expand westbound views toward the city of San Francisco by allowing views around YBI, because of their northerly and southerly locations, respectively, in comparison with the existing East Span. Replacement Alternative N-2 would expand views to a lesser degree, because it would closely follow the alignment of the existing East Span.

4.3.3 Impacts on Views to the Bridge

The changes in visual quality due to the project alternatives have been analyzed from 20 viewpoints around the Bay Area, as described in Section 3.3.3 — Viewer Groups and Viewpoints. Generally, the changes that would occur with each of the various project alternatives and design variations would be similar from each of the viewpoints. The analysis from five viewpoints has been included in the FEIS to represent the changes in visual quality from each location. These viewpoints are Richmond (from the north), the Oakland Touchdown area (from the east), the Oakland-San Francisco Ferry (from the south), TI (from the west), and the Nimitz House on YBI. This analysis included computer-generated visual simulations.

Impact of Build Alternatives

The retrofit alternative would have a negligible impact on visual quality from distant viewpoints, because the structural elements added to the East Span would not be perceptible. For some of the closer viewpoints, the retrofit alternative would have a minimally adverse impact on viewers, as the additional structural elements (new columns and strengthening of existing columns) would obstruct views underneath the bridge.

The main span design variations (self-anchored suspension [preferred design variation] and cable-stayed) would result in the most favorable impact upon visual quality regardless of the viewpoint location. Typically, this is due to the increase in the vividness of the span. Also, overall unity would occur with the self-anchored suspension main span. While conditions would vary at individual viewpoints, overall the three replacement alternatives (N-2, N-6 [Preferred], and S-4) would result in virtually identical visual impacts.

The skyway design variation would result in the greatest reduction in visual quality. Typically, this impact would be due to a reduction in the vividness and intactness of the span caused by the simpler structure and thinner bridge deck. While conditions would vary at individual viewpoints, overall the alignments of the three replacement alternatives under the skyway design variation would result in virtually identical visual impacts.

Analysis from Representative Viewpoints

Richmond Marina.

Retrofit Existing Structure Alternative. The retrofit alternative would have a negligible impact on visual quality. The long distance from this viewpoint to the East Span would make changes to the columns and support structures imperceptible.

Skyway Design Variation. The skyway design variation would have a minimally adverse impact on visual quality, due to its reduction in vividness (see Figure 4-4 in Appendix A). While it would remain at a favorable viewing angle, the simplicity of the structure would eliminate the striking and distinctive nature of the existing East Span.

Main Span Design Variations. The self-anchored suspension (preferred design variation) and cable-stayed design variations would have a minimally beneficial impact on the visual quality of the view towards the East Span. The main span tower would add landmark strength and distinctiveness, but the distance between the viewpoint and the East Span would make its distinct elements difficult to discern.

The self-anchored suspension (preferred design variation) and cable-stayed design variations would have a beneficial impact on the overall visual quality from the Richmond Marina, due to the increase in the vividness of the East Span and overall unity of the view (see Figure 4-5 in Appendix A). Unity would increase the greatest amount (from moderate-to-high to high) for the self-anchored suspension main span, due to the visual similarity, prominence, and shape compared with the SFOBB West Span (which is visible from the vantage point). Unity would increase less (remaining at moderate-to-high) with the cable-stayed main span, because its shape would not echo the cable forms of the SFOBB West Span.

Oakland Touchdown Area.

Retrofit Existing Structure Alternative. The retrofit alternative would result in a minimally adverse impact on visual quality of the view toward the East Span, due to the increase in view obstruction. New support columns and other structural elements added as part of the retrofit alternative would decrease views beneath the East Span.

Skyway Design Variation. The skyway design variation would result in a minimally adverse impact on visual quality, due to the slight decrease in the vividness of the East Span (although the East Span’s close proximity and prominence mean vividness would still remain high) (see Figure 4-6 in Appendix A). In addition, with Replacement Alternatives N-2 and N-6 (Preferred), there would be a slight increase in view obstruction. These alternatives would provide views similar to the existing East Span, although its more gradual rise from east to west would obstruct views from beneath the East Span to the north.

Main Span Design Variations. The self-anchored suspension (preferred design variation) and cable-stayed design variations would result in a minimally beneficial impact on visual quality of the view toward the East Span, due to the increase in vividness and unity and the fact that the East Span occupies much of the larger view (see Figure 4-7 in Appendix A). The main span tower would add landmark strength and distinctiveness. Vividness would increase the most with Replacement Alternatives N-6 (Preferred) and S-4, because the main span tower would be at a more favorable viewing angle (closer to 45 degrees) than Replacement Alternative N-2.

Unity would increase most with Replacement Alternatives N-2 and N-6 (Preferred), though the overall impact is slightly lessened by the high visibility, from this viewpoint, of approximately 30 support columns on YBI. Compared to Replacement Alternatives N-2 and N-6, Replacement Alternative S-4 would produce less of an increase in unity because portions of the SFOBB West Span would be visually obstructed. With all replacement alternatives, unity would increase more with the self-anchored suspension main span, due to the visual similarity, prominence, and shape compared with the SFOBB West Span and Golden Gate Bridge (which are visible from the vantage point). Unity would increase less with the cable-stayed main span, because its shape does not echo the cable forms of the SFOBB West Span.

Oakland-San Francisco Ferry.

Retrofit Existing Structure Alternative. The retrofit alternative would result in a negligible impact on visual quality. New support columns and other structural elements added as part of the retrofit alternative would decrease views beneath the East Span. However, views beneath the East Span would be constantly changing as the ferry travels across the Bay, thereby minimizing the view obstruction created by the new columns and structural elements.

Skyway Design Variation. The skyway design variation would result in a minimally adverse impact on visual quality, due to the decrease in its vividness (see Figure 4-8 in Appendix A). While it would remain at a favorable viewing angle and would be relatively close, the simplicity of the skyway design variation would reduce the distinctive nature of the existing East Span. The reduction in the vividness would be less perceptible with Replacement Alternative S-4, because it is the closest replacement alternative to this viewpoint. Vividness would reduce the most with Replacement Alternative N-6 (Preferred).