The National Transportation Safety Board is looking into a hidden danger on the highways: A nationwide shortage of parking spaces for large trucks. 

The shortage results in many drivers stopping on the sides of ramps — sometimes with fatal consequences.

Mario Gonzalez died in July on his way home from visiting his family when his pickup slammed into the back of a semi-truck parked on the side of a rest stop service road off Interstate 37 south of San Antonio. Gonzalez was speeding before he hit the brakes seconds before the impact. It was dark and the big rig did not have lights on.

"Losing him has left a hole in our family. A hole that nothing's going to fill," his daughter Lori told CBS News.

His family is now suing the truck company, which denies any wrongdoing.

"It doesn't take a lot of professional experience to understand the dangers of an 18-wheeler parked on a roadway at night in the dark," said Bob Hilliard, the attorney representing the Gonzalez family.

Gonzalez died two days after a hauntingly similar crash in Illinois killed three people when a Greyhound bus hit several big rigs parked along a rest stop access road.

The American Trucking Associations says drivers are forced to park in such areas because there is only one rest area  parking space for every 11 trucks on the nation's roads. 

In multiple states, CBS News found big rigs parked on freeway and rest stop shoulders and crowding roads leading into rest stops that were already full of parked trucks.

Investigators for Gonzalez's family shot video of the rest area where he died, showing that it was jammed with trucks on both sides of the road. Laws vary by state, but Texas does not prohibit parking on the shoulder.

Danny Schnautz, president of Clark Freight Lines in the Houston area, said the lack of parking, coupled with strict drive time rules, forces truckers into unsafe situations.

"We have to be safe," Schnautz said. "We tell drivers to realize that cutting their day short is better than putting someone in an unsafe position."

But finding a spot can be "impossible a large percent of the time," said Schnautz.

There were 4,000 injury accidents involving big rigs near interstate on and off ramps in 2020, according to the Federal Motor Carrier Safety Administration. There were 55 fatal accidents of that kind that year.

"This is not just a quality-of-life issue for truck drivers who deserve a good convenient, safe place to park, but also it's a safety issue for the entire system," said Transportation Secretary Pete Buttigieg.

While a bill authored by Congressman Mike Bost, Republican of Illinois, giving states an additional $755 million to expand existing truck parking languishes in Congress, the Department of Transportation is providing grants to expand truck parking in several states.

As for the Gonzalez family, they are pushing to ban parking on the side of the road entirely.

Kris Van Cleave

Kris Van Cleave is CBS News' senior transportation and national correspondent based in Phoenix.

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