Recent research shows better crash compatibility between cars and today's SUVs offers some protection for drivers, but pickups still represent an outsize danger when they collide with cars — and the weight imbalance is probably the reason.

From 2013 to 2016, pickups were 2.5 times as likely to be involved in a crash that was fatal for a car or minivan driver than other cars and minivans, according to research from the Insurance Institute for Highway Safety.

While pickups remain a problem, the data indicates that the trend toward better crash compatibility between cars and SUVs began several decades ago and has continued.

Specifically, the new study shows that in 2013 to 2016, the rate that car drivers were killed in crashes with 1- to 4-year-old SUVs was just 28% higher than those killed in car-to-car crashes.

Those rates are significant when compared with data from 1989 to 1992, which show the rate that car drivers died in crashes with 1- to 4-year-old SUVs was 132% higher than that of car drivers killed in crashes with other cars. From 2009 to 2012, the fatality figures improved — with the rate car drivers killed in collisions with SUVs 59% higher than those killed in car-to-car crashes.

The Institute traces improved compatibility and better protection to a 2003 voluntary commitment by automakers that the Institute helped broker. Manufacturers focused on stronger structures and side airbags in cars and minivans as well as newer SUV designs that lowered the vehicles' front ends to better align with cars' energy-absorbing structures.

However, pickup compatibility is still lacking, notes the Institute.

To see how much of the remaining problem with pickups is due to weight differences versus design issues, IIHS researchers conducted a series of tests with only vehicles weighing between 3,500 and 4,000 pounds. 

These results point to weight differences as a likely source of continued incompatibility for pickups.

Design continues to play a key role. More sophisticated designs that do a better job of managing forces in a crash, along with electronic stability control and other crash avoidance features, have made the sheer weight of a vehicle less important, notes the Institute. Still, the research indicates that reducing the weight of the heaviest vehicles by switching from steel to aluminum can improve safety for other road users without sacrificing occupant protection.