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Project Development Workflow Tasks (PDWT)
Part 3 - Identify Project Need and Project Initiation Document
II. Project Initiation Document
D. Analyze Alternatives (WBS 150.15) - Prepare and Obtain Approval for Design Exceptions (WBS 150.25.10)
The review of the standards prior to beginning any design work presents items to bear in mind during the preliminary design work. The design standards must be applied to the maximum extent reasonable using sound engineering judgment. However, the project must also balance the need for safe, efficient and maintainable transportation systems with environmental, social, aesthetic, and economic impacts. Sometimes in doing so, the project engineer may consider the use of non-standard features as elements of the design
The subject of Design Standards is discussed in Highway Design Manual Chapter 80, Application of Design Standards. Design standards fall into one of the following categories:
Mandatory standards pertain to requirements of the law or regulations, such as those embodied in FHWA’s 13 controlling criteria. The 13 criteria are design speed, lane width, shoulder width, bridge width, horizontal alignment, vertical alignment, grade, stopping sight distance, cross-slope, super elevation, horizontal clearance, vertical clearance, bridge capacity (See Index 108.3 of the Highway Design Manual). All (except bridge capacity) govern most of the mandatory standards that are written in the Highway Design Manual. Table 82.1(A) is a directory of Mandatory Design Standards. Advisory Standards are also important but allow more flexibility. Table 82.1 (B) provides the directory of Advisory Design Standards
Since the topics in the HDM address both mandatory and advisory standards within the same discussion, careful attention must be made to the format and wording of the information. Mandatory standards use the word “shall” and appear boldface while advisory standards use the “should” and are underlined. Permissive standards are all other standards and have no requirement for application. Permissive standards use the words “may” or “ should” but do not have any special formatting.
Perpetuating a non-standard condition or proposing the use of non-standard design feature requires justification and documentation for all capital improvement projects including Major projects, safety, rehabilitation, Minor A, and Minor B projects. Under certain circumstances, CAP-M projects may also require design exceptions (see “Capital Preventive Maintenance Program Guidelines”, September 26, 2000). Where approval of the non-standard features, affects the cost, scope or schedule of the project, the HQ Design Reviewer should be contacted at the earliest possibility during the preliminary design effort. If the HQ Design Reviewer is in agreement with the need and justification for a Design Exception, then the project engineer may prepare a Fact Sheet, have it reviewed, and move the proposed Design Exception forward to the Design Office Chief. If the project manager and the Design Office Chief concur with the proposal for a mandatory design exception, the project engineer may then present the proposed Design Exception to the HQ Design Coordinator. project engineers should not present proposed Design Exceptions to the HQ Design Coordinator without prior review by the Office Chief. As with any process requiring approval, there may be several reviews and discussions before the design element is finalized for approval.
Mandatory Design Standard
The Design Coordinator (DC) must approve exceptions to Mandatory Design Standards. The process for obtaining approval of Exceptions to the Mandatory Design Standard is discussed in the PDPM under Chapter 21, Section 1. The project engineer must complete and submit to the Design Coordinator a Mandatory Design Exception Fact Sheet requesting review and approval of the exception. The Fact Sheet attached to the Design Memorandum dated 9/25/00 has superceded the Fact Sheet found under Appendix BB of the PDPM. The memorandum and Fact Sheet can be accessed throughthe Design Intranet at http://www.dot.ca.gov/hq/oppd/design/m092500.htm.
All PIDs, except a PSR-PDS that has a full standard alternative, should not be signed prior to approval of exceptions to mandatory design standards per instructions included in Appendix L of the PDPM.
Following the Design Coordinator's approval, two copies of the Fact Sheet must be transmitted to HQ Design, Attention: Design Exception.
Advisory Design Standard
The Design Office Chief is delegated the authority to approve exceptions to Advisory Design Standards. Each district either has its own procedures for exceptions to Advisory Design Standards, or follows the format of the Mandatory Design Exception Fact Sheet to document the exception.
All Fact Sheets should be reviewed by the appropriate District Program Advisor (Manager) the District Design Office Chief, and if appropriate, the Traffic Operations Liaison Engineer and FHWA Area Engineer.
Preparation of a Design Exception Fact Sheet can generally be accomplished from a few days to a few weeks if the appropriate information was developed during alternatives development, including defining impacts, doing safety evaluations, figuring costs for standard, and, for some, an operational analysis. Assuming the Fact Sheet is well written with clear exhibits, the review and approval process can be accomplished quickly, but often stretches out months due to poor organization, internal inconsistency, or poor justification. A design exception could require four months to provide sufficient time for reviews of draft documents and then final approvals.
- (Chapter 80, “Application of Design Standards”)
- (Table 82.1(A) Mandatory Standards & (B) Advisory Standards)
Design Memorandum, (March 26, 2002, “Purpose, Application, and Approval Authority for Design Exceptions")
Design Memorandum, (September 25, 2000, “Fact Sheet for Exceptions to Mandatory Design Standards")
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This page last updated November 20, 2010