Each year, electric vehicles (EVs) are becoming a larger portion of the vehicle fleet. While the total number of EVs is currently small compared to their internal combustion engine (ICE) counterparts, the rate of growth continues to increase year over year. The characteristics of EVs pose many challenges to our transportation system moving forward. For example, their effect on roadside safety hardware has the potential to be significant based on their increased weight, lower center of gravity, and different crush stiffness. EVs are considerably heavier than comparable ICE vehicles. For example, the Ford Lightning EV pickup truck has a base curb weight ranging from 6,015 lb to 6,893 lb depending on battery range and trim package. Depending on the engine configuration, the Ford F-150 ICE pickup has a base curb weight range of 4,465 lb to 4,696 lb for a 4x2 drivetrain and 4,705 lb to 4,948 lb for a 4x4 drivetrain for the same cab style (SuperCrew®) and pickup box style (5.5-ft Styleside) as the Ford Lightning. Similar weight differences are found when other EVs and ICE vehicle platforms are compared.

The AASHTO Manual for Assessing Safety Hardware (MASH) discusses that impact severity is a good indicator of the magnitude of loading on a longitudinal barrier. Given a set of MASH impact conditions (i.e., impact speed and impact angle), the impact severity associated with an EV will increase linearly with the weight of the vehicle. One Ford Lightning configuration has a 32 percent increase in impact severity compared to MASH Test 3-11 with the 5,000-lb ICE pickup truck. EVs like the Rivian R1T pickup and Chevrolet Silverado SUV’s have even greater weight and impact severity.

This raises a significant concern related to electric vehicle compatibility with some categories of roadside hardware, such as various types of longitudinal barriers (e.g., guardrail, median barriers, bridge rails), terminals, crash attenuators, breakaway support structures, and other devices. Many roadside safety features are optimized for the currently prescribed MASH design impact conditions and may have little or no factor of safety for accommodating more severe impacts. The increase in vehicle weight associated with electric vehicles will place more structural demand on barrier systems and, in some instances will necessitate their redesign. Recent crash testing has confirmed this when a Rivian R1T EV pickup truck penetrated a Midwest Guardrail System (MGS) under MASH Test 3-11 impact conditions, thus failing the MASH structural adequacy criterion. Research is needed to address these issues to prevent us from getting too far behind the design curve and experiencing a potentially significant increase in roadway departure crash fatalities. Note that any advancements made to accommodate EV impacts would likely have an added safety benefit of accommodating heavier ICE vehicles as well.

The ever-growing market share of electric vehicles will also affect other aspects of our transportation system beyond roadside safety hardware. The lack of gas tax revenue strains the resources that DOTs allocate for new construction and renovation projects. The increased weight of EVs can affect loading on our pavements and bridges. Some multi-level parking garages have already been suspected of collapsing due to the unexpected weight of electric vehicles. Roadway geometric considerations of electric autonomous semi-trucks on the roadway infrastructure (e.g., driveway and intersection turning radii and templates) will also need to be accounted for in the future.

These are only a few of the areas requiring further research and investigation that can be addressed under this program. Many of the research needs associated with EVs are common amongst the states, making a pooled fund approach of combined resources an ideal way to address them. This Pooled Fund is focused on providing a coordinated program of EV research that will develop solutions to meet identified needs.  This will benefit the participating members in numerous ways, not the least of which is enhanced safety. 

The objective of this Pooled Fund is to assist transportation agencies in designing safe, reliable, and efficient transportation infrastructure for the ever-growing EV fleet. One primary focus of this research program will be to improve roadside safety hardware to address identified performance limitations. Standard W-beam guardrail is the most common longitudinal barrier system used across the country, and crash testing has already demonstrated its inability to contain EVs. Other current roadside safety standards will be tested under NCHRP Project 22-61. This program will support the next important research step of improving the design of hardware found to be noncompliant with MASH criteria when tested with EVs.

The scope of this Pooled Fund will also include other needed EV research areas, such as the effects of EV loading on transportation infrastructure and roadway geometric design impacts. Given the growing portion of electric vehicles across the country, all states will benefit from participation in this Pooled Fund program. 

Representatives of participating states will be convened as a technical committee to identify common research needs, select and prioritize research tasks, and provide oversight of these tasks. Specific activities may include but are not limited to: design, analysis, testing, and evaluation of roadside safety devices to accommodate EVs, the development of guidelines for the use, selection, and placement of these devices, investigating the effect of electric vehicle loading on transportation infrastructure, investigating the impact of electric vehicles (particularly large semi-trucks) on roadway geometrics, and other topics identified by the technical representatives of the participating state DOTs.

The identification, description, selection, and prioritization of research issues will be made by the technical committee on an annual basis, unless emerging issues require committee decisions in the interim. Computer modeling and simulation, full-scale crash testing, crash data analysis, cost effectiveness analysis, and other modeling and forecasting tools will be employed as needed to investigate the prioritized EV research tasks. 

TxDOT will serve as the lead state and chair of the technical committee and will enter into an agreement with Texas A&M Transportation Institute (TTI) to perform the research works associated with the projects selected by the technical committee. TTI will report back to the committee on a regular basis, seeking the committee's guidance when appropriate. At a minimum, participating states must commit $50,000 per year for three years to participate in the pooled fund project.