It shouldn’t come as a surprise that a vehicle with more mass can do more damage, but recent research from the Insurance Institute for Highway Safety (IIHS) suggests that the danger big SUVs pose to cyclists is more nuanced than that.

A study led by IIHS statistician, Sam Monfort, looked at not only the rate and severity of injuries to cyclists caused by cars and SUVs, but also the way that the damage was inflicted upon the victims.

Monfort looked at 71 bicycle crashes in Michigan, compiled by the International Center for Automotive Medicine’s Pedestrian Consortium. All involved cyclists over the age of 15, and a single car or SUV. His analysis found a clear pattern.

“SUVs tend to knock riders down, where they can also be run over, rather than vaulting them onto the hood of the vehicle,” said Monfort. “That’s probably because the higher front end of an SUV strikes the cyclist above their center of gravity.”

Read: On-Road Fatalities Level Off For Drivers In 2022, But Are Still On The Rise For Pedestrians And Cyclists

 SUVs Don’t Just Hit Cyclists, They Run Them Over, Too

In all accidents, injuries to the lower body were common, and head injuries were a frequent feature of the most severe injuries. The rate of head injuries is a useful gauge of how dangerous the crash is to the cyclist.

Monfort used the Abbreviated Injury Scale (a standard industry test used to assess injuries by body region) and found that the average scores for head injuries were 63 percent higher in accidents involving SUVs than those involving cars.

Notably, the research found that there were no significant statistical differences in injuries to other regions of the body between cars and SUVs. Despite that, trauma to the body as a whole was 55 percent higher for crashes involving SUVs than cars.

To help understand why head injuries were so much higher, Monfort looked at the 44 incidents that had information about how the cyclist moved after initial impact. In those accidents, only SUVs caused injuries by running cyclists over.

The data also suggested that SUVs tend to cause the most injuries with their wheels or undercarriage, after knocking cyclists to the ground. In the eight accidents with information about what part of the vehicle actually hurt the cyclist, the wheels or undercarriage of SUVs were responsible for 82 percent of head injuries.

All together, it paints a grisly picture of what happens when an SUV hits a cyclist. That’s a particular concern, because America’s love of larger, and crucially taller, vehicles coincides with rising rates of fatalities among cyclists. In 2020, 932 were killed on U.S. roads, up 50 percent from 2010.

 SUVs Don’t Just Hit Cyclists, They Run Them Over, Too