The AASHTO Manual for Assessing Safety Hardware (MASH) requires full-scale crash testing of roadside hardware (RSH) using worst practical impact conditions, which should be representative of the composition of vehicles involved in run-off-road crashes and of the roadside departure speeds and angles. Previous NCHRP projects have led to changes in standard test conditions and test vehicles. MASH was introduced in the mid-2000s and updated the standards and evaluation criteria for choosing which passenger cars and pickup trucks to crash test. A midsize test vehicle was also introduced. After exploratory crash testing for each of these changes in test vehicle selection criteria, a narrow range of makes and models were informally adopted as the preferred test vehicles, offering reproducible and economical outcomes.
NCHRP Project 20-07(372), "Evaluation of MASH Test Vehicles," indicated a significant decline in new passenger car sales and a rise in new light truck sales since 2014, driven primarily by compact utility vehicle (CUV) sales. Hence, updates for the selection criteria used for standardized passenger car and light truck test vehicles were recommended, as was exploratory full-scale testing to evaluate RSH using the CUV class of test vehicle. Pilot testing evaluating existing MASH-compliant RSH using the new proposed vehicles, with emphasis on the CUV class, is needed to ensure that testing criteria remains representative of practical, worst-case impact conditions.
The objectives of this research are to
- Determine which test vehicles and corresponding characteristics are representative of the changing vehicle fleet,
- Conduct full-scale crash tests of previously tested MASH-compliant RSH using representative vehicles,
- Identify RSH performance differences between existing MASH-compliant test vehicles and new representative vehicles, and
- Recommend vehicle types and corresponding characteristics for RSH crash safety analysis.
Accomplishment of the project objectives will require at least the following tasks.
Task 1. Review literature and state-of-practice. Resources may include pertinent issues with existing test vehicles, changes in vehicle fleet and characteristics, and vehicle sales data.
Task 2. Analyze current vehicle data to determine representative vehicle specifications. Determine characteristics of the changing vehicle fleet and representative vehicles. Contrast characteristics of the representative vehicles with current MASH vehicle types (e.g., Test Level 3).
Task 3. Develop draft test plan for full-scale crash tests with representative vehicles. Select and justify testing of MASH-compliant nonproprietary RSH for full-scale crash tests. The test plan shall include (1) a method to compare crash test results based on MASH evaluation criteria and previous MASH crash test vehicle results, and (2) a process for updating NCHRP on crash test developments.
Task 4. Submit an interim report covering the findings of Tasks 1–3. Present the report to NCHRP at an in-person meeting. NCHRP approval of the report must be obtained before work on remaining tasks begins.
Task 5. Conduct full-scale crash tests and analyze results. Testing must be conducted per MASH requirements. Identify RSH performance differences between existing MASH-compliant test vehicles and new representative vehicles.
Prepare a technical memorandum summarizing the findings of Task 5. Present findings from the technical memorandum to NCHRP at an online meeting. NCHRP approval of the memorandum must be obtained before work on remaining tasks begins.
Task 6. Determine recommended vehicle types and corresponding characteristics for RSH crash safety analysis. Identify specific vehicles with these characteristics.
Task 7. Develop (1) a framework for updating vehicle specifications as the fleet evolves, and (2) an implementation plan for future MASH revisions, with consideration of potential implementation impediments.
Prepare a technical memorandum summarizing the findings of Tasks 6–7. Present findings from the memorandum to NCHRP for approval. NCHRP approval of the memorandum must be obtained before work on Task 8 begins.
Task 8. Submit final deliverables. The conduct of research report shall cover Tasks 1–7.
STATUS: Proposals have been received in response to the RFP. The project panel will meet to select a contractor to perform the work.