While the majority of automobile crashes involve vehicle-to-vehicle impacts, a number of incidents involve vehicles impacting roadside structures. NCAC's Highway Safety and Infrastructure Research Group analyzes those structures, which include guardrails and other protective barriers, roadway signs and other fixed objects, with the ultimate goal of improving roadside structure design and enhancing safety.
This group's research has supported the efforts of the FHWA, many state departments of transportation, and most recently the U.S. Department of State to improve roadside hardware safety and reduce serious injuries in the United States and abroad. Their work focuses on building comprehensive and robust models for evaluating structural crashworthiness during impacts, so that highway engineers can make quick, well-informed and cost-effective decisions. These tools have helped FHWA identify potential safety problems and adopt new regulations or make recommendations for resolving them.
Highway safety and infrastructure research at the NCAC focuses on a variety of structures, including:
- Roadside Hardware, such as portable concrete barriers, secure mailboxes and w-beam guardrail systems. To meet constantly changing transportation safety needs, NCAC undertakes dozens of projects to evaluate roadside hardware designs to ensure that safety criteria are kept up to date and structures are designed or redesigned as necessary to meet changing traffic needs.
- Anti-Ram Protective-Barriers, such as bollards, concrete-reinforced walls and pile/picket fences, which are used regularly to protect buildings. NCAC's work helps reduce structure costs and improve aesthetics without compromising the structure's protection performance.
Traditional methods for evaluating roadside hardware performance relied solely on full-scale crash testing. Depending on the type of hardware structure, the process sometimes involved several hundred costly full-scale crash tests before engineers achieved a satisfactory design. NCAC developed new modeling and simulation methods that reduce the need for multiple full-scale tests, and that anticipate and validate results of the tests that are conducted. By combining modeling and simulations with full-scale testing, NCAC has made the analysis and testing process for roadside hardware more efficient and cost-effective than ever.
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The Highway Safety and Infrastructure Research team is also using this approach to help the U.S. Department of State develop the security barriers used to protect U.S. embassies and other buildings against vehicle attacks.
The team developed finite element (FE) computer models of such anti-ram devices as bollards, walls and fences to assess performance and improve design. Several anti-ram devices were evaluated, tested and improved, and were deemed strong enough to withstand vehicle impacts and prevent vehicles from penetrating protected areas.