Electric vehicles typically weigh significantly more than gasoline-powered cars and can easily crash through steel highway guardrails that are not designed to withstand the extra force, raising concerns about roadside safety, according to a crash test by the University of Nebraska. Electric vehicles typically weigh 20 percent to 50 percent more than gas-powered vehicles due to their batteries that can weigh almost as much as a small gas-powered car. For example, Ford’s F-150 Lightning EV pickup is 2,000 to 3,000 pounds heavier than the same model’s combustion version. The Mustang Mach E electric SUV and the Volvo XC40 EV are roughly 33 percent heavier than their gasoline counterparts. Besides the weight factor, electric vehicle batteries are typically installed under the vehicle, giving it a low center of gravity. Because of these differences, guardrails do little to stop electric vehicles from pushing through the barriers typically made of steel. Paradoxically, the Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) is currently proposing a steep hike in fuel economy standards that will result in forcing two-thirds of new auto sales to be electric by 2032.
The U.S. guardrail system was not made to handle vehicles greater than 5,000 pounds and there are a lot of new vehicles in the 7,000-pound range being manufactured. The extra weight of electric vehicles comes from their outsized batteries needed to achieve a travel range of about 300 miles per charge. The extra weight also poses a problem to faster wear and tear to residential streets and driveways, vehicle tires and infrastructure like parking garages. A lot of parking structures were built to hold vehicles that weigh 2,000 to 4,000 pounds and the cities in which they predominate are most likely to attract EV buyers.
Last fall, engineers at Nebraska’s Midwest Roadside Safety Facility watched an electric-powered pickup truck hurtle toward a guardrail installed on the facility’s testing ground on the edge of the local municipal airport. The nearly 4-ton 2022 Rivian R1T tore through the metal guardrail and hardly slowed until hitting a concrete barrier yards away on the other side. Rivian trucks weigh nearly 2,000 pounds more than conventional pickups. Last year, the National Transportation Safety Board expressed concern about the safety risks heavy electric vehicles pose if they collide with lighter vehicles. The Rivian truck tested in Nebraska showed almost no damage to the cab’s interior after slamming into the concrete barrier, which indicates that they offer protection to their occupants if the electric vehicle is big enough and heavy enough.
While heavier vehicles are safer for their own occupants, they are more hazardous for the occupants of other vehicles. In crashes, the “baseline fatality probability” increases 47 percent for every 1,000 additional pounds and the fatality risk is even higher if the striking vehicle is a light truck (SUV, pickup truck, or minivan), according to the National Bureau of Economic Research. The average weight of U.S. vehicles increased from about 3,400 pounds to 4,300 pounds over the last 30 years as Americans switched from passenger cars to pickups and SUVs as Corporate Average Fuel Economy (CAFÉ) standards downsized regular passenger cars.
But the purpose of guardrails, found along tens of thousands of miles of U.S. roadway, is to keep passenger vehicles from leaving the road. Guardrails are intended to keep cars from careening off the road at critical areas, such as over bridges and waterways, near the edges of cliffs and ravines and over rocky terrain, where injury and death in an off-the-road crash is much more likely. Guardrails are generally a safety feature of last resort.
Electric vehicles also have very high horsepower ratings, allowing them to accelerate quickly even in crowded urban areas, which drivers are typically not trained to handle. Also, many newer electric SUVs are tall with limited visibility that poses risks to pedestrians or drivers of smaller vehicles.
A similar finding to the Nebraska study was from a preliminary crash test sponsored by the U.S. Army Corps of Engineers’ Research and Development Center. A Tesla sedan crashed into a guardrail, lifted it and passed under it. Both tests show the guardrail system is likely to be overmatched by heavier electric vehicles. More testing, involving computer simulations and test crashes of electric vehicles, is planned and needed to determine how to engineer roadside barriers that minimize the effects of crashes. Better collaboration between transportation engineers and vehicle manufacturers is also needed.
Conclusion
While their design makes it more difficult for electric vehicles to roll over due to their low center of gravity, crash tests show that road barriers and guardrails may not be equipped to protect electric vehicle drivers. The University of Nebraska and the U.S. Army Corps of Engineers both conducted EV crash tests with guardrails, finding similar results. The guardrails were not built for the weight of many electric vehicles, nor were U.S. roads, driveways, parking garages and vehicle tires. Despite this safety issue and numerous other issues with electric vehicles, including higher costs, dependency upon China for necessary minerals, higher insurance costs, range anxiety and tires wearing out before 10,000 miles, President Biden wants 50 percent of new car sales in the United States in 2030 to be electric.
*This article was adapted from content originally published by the Institute for Energy Research.