Electric vehicles (EVs) are increasing in popularity and are among the fastest-growing segments in new vehicle sales. Battery-electric vehicles (BEVs) are the highest-selling class of EV. BEVs use a unique frame construction (i.e., a “skateboard” chassis) with a heavy battery pack located below the occupant’s floorpan, and are heavier and have lower centers-of-gravity than internal combustion engine vehicles (ICEVs)—factors that could affect their crashworthiness with roadside features. A crash study was performed to compare the crash conditions for BEVs to ICEVs and hybrid-electric vehicles (HEVs) covering the numbers of vehicles, posted speed limits, crash locations, time of day, weather conditions, crash severities, and roadside fixed objects struck. Eight state departments of transportation provided crash data spanning 5 years that included vehicle identification numbers or make, model, and year combinations, which were used to isolate BEVs from ICEVs. Crash results were reviewed and EV crash conditions were found to be similar to those of ICEV and HEV crash conditions. Moreover, the frequency of run-off-road crashes was similar for BEVs and ICEVs. Because no substantial differences were observed between the two datasets, it is recommended that impact conditions described in the Manual for Assessing Safety Hardware be utilized during preliminary evaluation of roadside hardware using electric vehicles.

Roadside barriers are used to shield fixed objects near the roadway and are designed to mitigate the severity of run-off-road crashes near those fixed objects. The zone of intrusion (ZOI) defines the potential location of a vehicle component above and beyond the top face of the barrier during an impact, and therefore indicates if there is a potential that a fixed object located behind a barrier could interact with the vehicle during redirection. Previous ZOI envelope guidelines were based on older vehicle models and test results. Further review was required to update the guidelines for contemporary vehicles and impact conditions in accordance with the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). A literature review of full-scale crash tests and computer simulations were used to identify the ZOI envelope shapes for MASH test levels 2–5. Simulations were calibrated using test data and were used to investigate gaps in the full-scale test data. Conservative guidelines were developed from the combined simulation and test data, and recommended ZOI envelope shapes were developed that conservatively bounded the ZOI results. Results were presented for potential revision of ZOI envelope guidelines in the AASHTO Roadside Design Guide. Future recommendations to improve ZOI measurements in test data and simulation modeling were also presented.

Battery electric vehicles (BEVs) are rapidly becoming a significant part of the U.S. vehicle fleet. These vehicles possess significant design variations from conventional, gas-powered vehicles, including increased curb weight, altered mass distribution, different frame structures, and altered vehicle geometry that may adversely affect the safety performance of existing roadside hardware. The objective of this research was to perform full-scale crash testing of BEVs with common roadside hardware to identify potential compatibility issues. Four full-scale crash tests were conducted according to American Association of State Highway and Transportation Officials’ Manual for Assessing Safety Hardware (MASH) requirements as part of the study using Telsa Model 3 sedans and Rivian R1T pickup trucks. Testing was performed on the Midwest Guardrail System, a high-performance concrete parapet, and an F-shape portable concrete barrier. Two crash tests on the Midwest Guardrail System failed to meet safety requirements owing to the Telsa Model 3 underriding the guardrail and the Rivian R1T rupturing the guardrail. Full-scale crash testing on the concrete parapet using the Telsa Model 3 resulted in occupant risk criteria that exceeded acceptable limits. Testing on the F-shape portable concrete barrier using the Rivian R1T found that the barrier was able to contain and redirect the vehicle, but the performance of the barrier system was at its functional limit. The crash test results provide insights into the compatibility issues of BEVs with current roadside hardware, and recommendations for research needs and additional actions to address these issues are suggested.

The objective of this project was to develop installation guidelines for the placement of the Midwest Guardrail System (MGS) in combination with roadside curbs to satisfy the Manual for Assessing Safety Hardware (MASH) Test Level 3 (TL-3). A combination of vehicle trajectory tests, LS-DYNA simulations, and MASH crash testing were used to achieve this objective. Two vehicle trajectory tests, using a 2270P pickup and an 1100C small car, were conducted with the vehicles traversing over a 6 in. tall, American Association of State Highway and Transportation Officials Type B curb at impact conditions consistent with MASH TL-3. The suspensions of LS-DYNA models for these MASH vehicles were updated, and validated to match the vehicle trajectories measured during the curb traversal tests. The updated vehicle models were then used to simulate MASH TL-3 impacts with the MGS set at various offsets behind the curb. An offset of 6 ft was selected as the maximum offset for the MGS behind the curb. Two MASH crash tests were conducted on the MGS placed behind the curb. A MASH 3-11 test was conducted with the MGS offset 6 ft behind a 6 in. curb to evaluate override and instability concerns, while a MASH 3-10 test was conducted with a 1 ft offset to evaluate underride and snag. Both tests passed MASH TL-3 safety performance criteria. Additional simulations showed that reduced impact speeds and angles did not cause any vehicle containment or stability concerns. Thus, the MGS with a height of 31 in. relative to the top of the curb was considered MASH TL-3 crashworthy when installed at offsets between 1 and 6 ft behind a roadside curb.