It’s not your imagination. Cars and trucks are getting larger. Next time you’re waiting in a parking lot, take a closer look at the sizes of new and old vehicles. Across the board, American trucks, SUVs, and sedans have been growing nearly every year, increasing in size and power. Even worse, vehicles are increasingly designed with high front ends that make them deadly in crashes.

“I would say it’s the clearest cause,” said Angie Schmitt, when I recently asked about larger and more dangerous vehicle designs.

Schmitt is an experienced transportation journalist and urban planner, who extensively researched the rise in pedestrian crashes for her new book, “Right of Way.” In it, she describes how and why American streets and vehicles became so deadly for people on foot, a trend that has spiked over the last decade.

“There’s been a big shift from sedans to SUVs, crossover SUVs, in particular,” explained Schmitt. “It’s much more profitable to sell SUVs. They charge about 10-15K additional dollars for an SUV over a sedan body design, [though] they cost about the same amount of money to make.”

It’s a trend that might have slipped your attention. Fewer people are buying smaller cars, and far more new purchases are large SUVs and trucks that tower over previous generations of vehicles. Even the humble Subaru Outback has grown in power, weight, and height over the last 15 years.

In order to track climate pollution, the EPA closely measures the size, weight, power and other trends for American vehicles. The resulting data show a steady increase in size of U.S. vehicles, made even more dramatic by the overwhelming shift away from sedans and toward SUVs over the last few years.

(One thing it does not analyze is vehicle design. Popular models like the Toyota Tundra, Nissan Armada, Cadillac Escalade, and nearly every pickup truck have high grills that increase risk for people involved in collisions.)

Unstoppable physics of vehicles crashes

At one level, the basic calculation of vehicle safety (the “F = M x A” equation from high school physics) is pretty straightforward. The bigger and faster they are, the harder they hit anyone in the way. Speed is probably the critical variable when it comes to safety for people on foot, but it turns out that overall size and design also play a key role. The higher design of SUVs and trucks, in particular, poses a massive problem for pedestrian safety.

“Two things happen with the physics of an SUV,” explained Nichole Morris, Ph.D., the lead researcher at the HumanFIRST Lab at the University of Minnesota, which studies pedestrian safety measures. “The first is transfer of force: If the nose of the SUV or truck hood is raised up, you get more of that transfer of force hitting more vulnerable parts of the body.”

According to Morris, raising the height of a bumper by a foot doubles the amount of force that’s delivered into a person’s body during a crash. The other consequence of taller and larger vehicles is that people tend to be thrown down instead of upward, leading to a direct impact with the pavement.

“The secondary impact [with the ground] is usually the part that tends to be the most fatal,” Morris explained. “With an SUV, the secondary impact is [often] the head hitting the ground — that huge force to your torso and your head strikes the ground.”

The physics of vehicle crashes also depends on the age and size of the person who is hit by the vehicle. For example, people over 60 years old are over four times as likely to die than younger people. Children are also, predictably, at far higher risk of death when hit by a vehicle.

“The physics are all working against pedestrians when it comes to SUVs or large trucks, [and] it’s really harmful for older pedestrians and for young children,” said Morris.

Local regulation is almost impossible

Vehicle design is a national issue that involves regulating automakers. As a result, there’s little that cities or counties can do about the increase in the size or deadly designs of vehicles. For example, the ongoing fight over Gov. Tim Walz’s proposed “Clean Cars” rules illustrates well how challenging it is for states to regulate auto manufacturers.

That hasn’t stopped some states from trying, as California’s emissions and fleet regulations have set the pace for other states of follow. Recently, New York State lawmakers floated a regulatory proposal squarely aimed at vehicle design. The proposal would put “warning labels” on dangerous SUVs and trucks that might dissuade buyers with better information about pedestrian and bicycle impacts.

“Ratings would be displayed when they’re sold, like fuel efficiency,” explained Schmitt. “They would be like the current 5-star safety ratings, [but] for the way vehicles affect people outside the cars.”

When asked about the warning label idea, Morris was a bit skeptical, pointing out that at lot depended on the details of when the warnings were displayed. Often when people are already at the dealership, they have their minds made up about what they want to purchase. Similarly, many such details get lost in the fine print of a purchase agreement.

In the meantime, a lot of work being done throughout the Twin Cities to boost traffic safety is effectively undermined by the increase in size and deadly designs in new motor vehicles. New bump-outs or reduced speed limits are even less of a deterrent as vehicles become larger and more powerful than ever before.

“[Cities] are supposed to spend all this money to create safe spaces for these dangerous machines to barrel through our streets,” said Morris, who is beginning a new study on improving crosswalk safety in the Twin Cities. “Until auto manufacturers take more responsibility for what they’re supplying, I don’t know what a good solution is.”