BACKGROUND

According to the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) crash tests, devices sometimes fail due to relatively insignificant damage to the vehicle, as MASH does not allow for any part of the device or vehicle component to enter the vehicle compartment. If there is any penetration, the device fails that test. Some deformation of the vehicle occupant compartment is allowed, but varies by area of the vehicle. Although engineering judgment and experience indicate that minor deformation/penetration does not normally pose a safety risk to occupants, MASH is very stringent in this area. 

As with many AASHTO publications, early editions often contain guidelines based on expert consensus rather than research, and as time goes on committees request research to address these areas. Without solid information on the risk posed to vehicle occupants from some minor types of crash test damage, the thresholds in AASHTO documents need to err on the side of caution (e.g., “no penetration into the occupant compartment”). As states, academia, and industry work to develop MASH hardware and fully implement MASH, some devices fail crash tests even though engineering judgement suggests that the devices appear to provide the desired protection to vehicle occupants. Research is needed to determine whether deformations and penetrations that appear to be relatively minor — but are currently cause for failed MASH crash tests — do in fact present a safety risk to vehicle occupants.

OBJECTIVES

The objectives of this research are to (1) evaluate the MASH limits for test vehicle deformations and penetrations by roadside safety features and vehicle components and (2) conduct tests to ensure the thresholds for test vehicle occupant compartment deformations and penetrations most appropriately represent potential safety risk to occupants in the current vehicle fleet.

Achieving these objectives would make MASH testing thresholds more realistic, which can lead to increased development and use of MASH devices.

RESEARCH PLAN

The research plan should (1) include a kick-off teleconference with the research team and NCHRP convened within 1 month of the contract’s execution; (2) address how the proposer intends to satisfy the project objective; (3) be divided logically into detailed tasks necessary to fulfill the research objective and include appropriate milestones and interim deliverables; and (4) incorporate opportunities for the project panel to review, comment on, and approve milestone deliverables. 

Accomplishment of the project objectives will require at least the following tasks.  

PHASE I

Task 1. Document historical occupant risk criteria for deformations and penetrations.

Task 2. Assess current MASH limits for test vehicle deformations and penetrations. This task should document examples of test vehicle deformations and penetrations that constitute failure under current MASH criteria.  

Task 3. Classify the examples of test vehicle deformations and penetrations based on the risk of occupant injuries.

Task 4. Develop a plan for conducting tests of vehicle occupant compartment deformation and penetration to demonstrate implications of changes to MASH criteria.   

Task 5. Prepare an Interim Report #1 that summarizes results from Tasks 1 through 4 and refines the Phase II work plan.

PHASE II

Task 6. Execute the testing program according to the approved Interim Report #1.

Task 7. Prepare an Interim Report #2 that (1) documents results and findings from Task 6 and (2) discusses implications for updating the MASH test for vehicle deformations and penetrations.  

PHASE III

Task 8. Meet with members of the TRB Roadside Safety Design Committee (AKD20) and the AASHTO Technical Committee on Roadside Safety to present results/findings from testing and implications for updating MASH. Collect feedback from meeting participants.

Task 9. Based on the testing program, prepare draft language for consideration by AASHTO to incorporate the research results in the next update of the AASHTO MASH (herein called AASHTO Deliverable).

Task 10. Prepare a final deliverable that documents the entire research effort. Final deliverables should include (1) a final research report documenting the entire research effort and findings; (2) AASHTO Deliverable; (3) prioritized recommendations for future research needs; (4) a PowerPoint presentation; and (5) technical memorandum on implementation.

STATUS: Proposals have been received in response to the RFP.  The project panel will meet to select a contractor to perform the work.