In the wee hours one night in July, a Greyhound bus heading to St. Louis turned onto an exit ramp leading to a rest area in Southern Illinois and hit three parked tractor-trailers, smashing its front, crumpling its roof and ripping off part of its side.

Three passengers were killed. The tractor-trailers were parked along the ramp’s shoulder, a common sight on the nation’s highways.

“It’s scary because it can happen in the blink of an eye,” said Carmen Anderson, 64, a South Dakota-based truck driver for America’s Service Line, who recently had to park on an off-ramp in North Carolina after not being able to find parking at rest areas or truck stops.

The accident in Illinois highlighted a widespread complaint among the nation’s truckers: Parking spots for commercial trucks are hard to come by.

As a result, truckers often take refuge in store parking lots, along the shoulder of highways and on ramps, though the legality of doing so varies by location. The shortage of parking is both inconvenient and financially costly for truck drivers, and it can lead to dangerous situations when truckers are forced to improvise.

Federal transportation officials and lawmakers are trying to bring some relief to truckers. Under the Biden administration, the Transportation Department has awarded tens of millions of dollars to projects around the country to build more truck parking, and a bipartisan proposal in Congress would allocate hundreds of millions more to address the issue.