The Impact of Vehicle Electrification on Safety

Our “How Vehicle Electrification Affects the Gas Tax” post from last year got us thinking of other changes that could flow from increasing numbers of EVs on streets…

The Federal government has set a target calling for 50% of new cars to be electric by 2030, and 100% by 2035, and many states have similar goals. The EPA announced new tailpipe emission standards in April of this year with the aim to encourage car manufacturers to shift their production even sooner. California has gone further and banned the sale of gasoline-powered cars by 2035. We’ve seen it asserted that this push for more EVs, while well-intentioned, could be at odds with the safety goals in the National Roadway Safety Strategy and Vision Zero commitment due to heavier vehicle weights.

We set out to determine whether the vehicle weight trends support the assertion that climate-driven EV policies clash with roadway safety goals, and further, how vehicle design and policy in the evolving EV market could alter the recently increasing rate of death and severe injuries on American roads.

Electric Vehicles – Impact on Weight Distribution and Implementation Scenarios

There is a lot of uncertainty around what the new fleet of EVs could look like as their adoption spreads. Using data to put the projected increase in vehicle weights into perspective, we looked at two scenarios for the adoption of EVs compared to the current vehicle weight distribution. First, we analyzed a scenario in which the forecasted share[1] of EVs would be made up of the most popular EV models today, like the Tesla 3 or the Chevy Bolt. Secondly, we analyzed a scenario in which the EV market might shift to vehicles more like our current vehicle distribution (i.e., more trucks and SUVs, fewer sedans and passenger cars). Here’s what we found.

In scenario 1: If market forecasts for the share of EVs turn out to be accurate and the current weights of vehicles hold constant for all vehicles, our new vehicle fleet in 2030 could be 2% heavier on average than it is today. In scenario 2: If EVs began to take on characteristics that are more similar to gasoline-powered cars, with more SUVs and pickup trucks on the road, that increase could be closer to 9% on average.

Both scenarios show that EVs contribute to a heavier fleet, but they follow a trend of increasing weights that have been well-established for decades. While electric vehicles are poised to contribute to the increasing weight of vehicles, their adoption could be designed to slow this trend. The size and weight of U.S. vehicles has steadily climbed over the last three decades, much prior to electrification. The share of gas-powered trucks, SUVs, and minivans has leapt from less than 25% of the market in 1985 to nearly 75% in 2022. Further, all vehicle types have been getting heavier, causing the average overall weight of the new vehicle fleet to climb by 34% since 1985. While electric vehicles are poised to contribute to the increasing weight of vehicles, their adoption could be designed to slow this trend.  

The future of road safety is heavily dependent on the size and shape of vehicles. If EVs dominate the future market, their design and the policies that shape them are going to play a key role in safety outcomes.

The U.S. Loves Big Cars – The Policy Choices and Market Forces That Led Us Here.

The American preference for large vehicles stems from the Corporate Average Fuel Economy (CAFE) standards introduced in the 1970s. To meet these standards, car manufacturers were incentivized to improve fuel efficiency mostly by shedding weight. However, an exception in the policy for light-duty trucks (originally intended to negate adverse impacts on jobs that required a large vehicle) created a loophole. As CAFE Standards exist today, pickup trucks, SUVs, and minivans can be classified as “light-duty trucks” allowing for more lax fuel efficiency requirements. This has had the effect of encourages car manufacturers to produce larger, heavier vehicles to meet their fuel efficiently targets.

Consumer preference for larger vehicles has been partially driven by a desire for passenger safety, as larger and heavier vehicles are less likely to result in injuries or fatalities for the people inside of them. Between sparse regulations for vehicle size, and a built environment that supports parking and driving big cars, there’s not much limiting how big our cars can get. Additionally, advancements in fuel efficiency have removed the prohibitive costs associated with fueling a large and heavy car, making them more appealing for everyday travel needs.

This trend of increasing vehicle size may continue with the rise of electric vehicles. Marketing for EVs tends to highlight size, power, and acceleration capabilities, which indicates that the shift away from gas-powered vehicles doesn’t mean a clean break from the tropes that have given us bigger and ever more powerful cars.

For over half a century, Federal policies have intentionally or not, supported vehicle fleet characteristics that decrease road safety for those outside the vehicle. Electric vehicles do not pose a new or unique threat to Vision Zero: they are simply the climate-friendly reimagination of a persisting contradiction between vehicle design and safety goals.