The Mitsubishi Mirage is one of the very lightest cars sold in the Seattle metro area, weighing in at a mere 2,029 pounds. The heaviest a commercial truck can weigh here in Washington is 105,000 pounds, which means a fully loaded tractor-trailer tips the scales at slightly more than 50 times as much as a Mirage.
It takes no imagination to know happens to occupants of the smaller vehicle when an 18-wheeler at maximum weight slams into it from behind.
Once a large, heavy commercial truck is rolling on an interstate highway, it’s difficult to slow it or stop it quickly, making rear-end truck collisions with passenger vehicles all too common.
Good safety news
A recent study of large trucks by the Insurance Institute for Highway Safety contains good news, however. Equipping heavy commercial trucks with forward-collision warning and automatic emergency braking (AEB) – systems currently available in new passenger cars – could eliminate more than 40 percent of rear-end crashes in which big rigs hit other vehicles from behind.
IIHS analyzed data from 62 carriers operating 18-wheelers and other trucks weighing at least 33,000 pounds. The nonprofit organization found that large trucks outfitted with forward-collision warning reduced rear-end crashes by 44 percent and that those with AEB reduced rear-end collisions by 41 percent.
The IIHS study covered 2017-19 and included about 2,000 crashes. The analysis excluded incidents that didn’t include injuries or significant property damage.
IIHS pointed out crashes involving large commercial trucks have risen nearly one-third since 2009. Two years ago, more than 4,100 people died in crashes involving big rigs, with 119 of those deaths in crashes in which the large truck rear-ended a passenger vehicle.
“This study provides evidence that forward collision warning and AEB greatly reduce crash risk for tractor-trailers and other large trucks,” said IIHS Director of Statistical Services Eric Teoh.
A look inside
Front-crash prevention systems bundle cameras, sensors and processors to monitor and analyze what lies ahead. Some systems include only forward-crash warnings which alert drivers, while AEB systems apply brakes to prevent collisions or reduce the vehicle’s impact speed.
An IIHS study of AEB in passenger vehicles found that the autobraking system has significant safety benefits. “AEB cuts rear-end crash rates in half and rear-end crashes involving injuries by 56 percent,” the IIHS stated.
For the new study, the IIHS compared trucks equipped with forward-collision warning alone, AEB and heavy trucks with no front-crash prevention technology at all. (The IIHS noted that “AEB systems generally include forward-collision warning too.”)
Benefits beyond crash reduction
The organization said AEB and front-crash warning systems are “both likely to have benefits beyond the reduction in crashes.” When a crash can’t be prevented entirely, the systems made the collisions less severe by reducing the impact speed of the big rig by more than 50 percent. The speed reduction, in turn, lowers the risks of severe injuries and fatalities.
The IIHS issued a call to the federal government to mandate inclusion of the limb- and life-saving safety systems in all new large commercial trucks.