Development of an Aesthetic / Low Maintenance Guardrail System
This project has recently begun and is in the stage of establishing the Project Steering and Technical Advisory Teams.
NOTE: above design is an example , no concepts currently selected
Standard metal beam guardrail (MBGR) is very expensive to maintain in locations with frequent vehicle impacts. In addition, local communities and agencies are increasingly demanding that Caltrans build highway projects that include roadside barriers with an aesthetic appearance, which standard W-beam guardrail does not provide. Some highway construction projects are actually delayed because the barriers are not acceptable enough in appearance. There are only a few aesthetic barriers approved under NCHRP Report 350 that are rated at Test Level 3 (TL-3).
Most are proprietary, expensive to build, and expensive to maintain. A guardrail that requires little maintenance, is aesthetically acceptable, and is non-proprietary needs to be developed.
To solve this problem, this research shall be broken up into two separate phases. The first phase will handle the design effort and the second phase will handle the developmental testing and crash-worthiness testing of the final product.
Caltrans has two basic problems with placing guardrail in certain locations:
- High maintenance where frequently impacted - Existing standard plan MBGR requires extensive maintenance after impacts from run-off-the-road vehicles. Along roadways with frequent impacts, there can be numerous sections of mangled and bent MBGR with leaning or broken posts. These damaged sections are totally ineffective in redirecting run-off-road vehicles as they await repair. When maintenance crews do finally schedule time to repair or replace, they are exposed to traffic hazards. If lane closures are required, not only are workers and motorists at risk, it costs Caltrans money and takes time away from other maintenance tasks. In addition, resulting traffic congestion costs motorists time and money. For an example of high maintenance costs, in Fiscal Year 2004 District 3 spent almost $87,000 working to maintain the 10.49 miles of MBGR on US50 just in Sacramento County alone.
- Lacking in aesthetics in scenic locations - MBGR stands out like a sore thumb in scenic areas. It detracts severely from the beautiful natural resources our highways cut through, like around Lake Tahoe, along the coast and through parks and forests. Several projects in Districts 3, 4, and 5 have specified acid-etched guardrail in response to demands from local agencies or groups (locals) for context sensitive highways. However, acid-etched guardrail is the same product with just the galvanized shine removed, and still leaves much to be desired aesthetically. Some projects have been delayed because the MBGR does not meet the approval of locals. Project managers are considering other guardrail options to establish context sensitive roadways, but they don't quite fit the need or budget.
The objective of this research is to develop and test a new guardrail system to NCHRP Report 350 Test Level 3 (TL-3). It will meet California's needs for an aesthetically pleasing guardrail and be able to sustain vehicular impacts with minimal or no damage. It will have a relatively low life-cycle cost, contain a minimum of parts for maintenance stations to stock, and be easy to repair or replace if required. The research proposed will design such a system from the ground up, exploring different materials and designs to meet these objectives. This new design will not be intended to replace the widely used MBGR, which should remain as the standard for locations where aesthetics are of no concern and vehicle impacts are infrequent. In addition to meeting these objectives, Caltrans' goals of safety, reliability, project delivery and stewardship will be addressed:
- Highways with the new guardrail will be safer for maintenance crews, not requiring major repairs and replacement after impacts.
- Congestion from guardrail maintenance work will be reduced, making routes more
- Projects with aesthetic options can be delivered more quickly, satisfying locals.
- Caltrans will be a steward of natural resources by establishing highways with context sensitive features.