Kind of like motel vacancy signs, new signs near three rest areas along eastbound Interstate 94 now tell truck drivers how many parking spaces are available.

The signs are part of a pilot project led by the Minnesota Department of Transportation and the University of Minnesota designed to give truckers real-time information about where they can find a safe place to pull off the road when they have reached their driving limit.

Federal regulations limit truckers to a maximum 70-hour workweek, down from 82 hours since tighter rules went into effect in July 2013. The rules, enacted to combat drowsy driving, require truckers who reach their weekly limit to rest for 34 consecutive hours before starting another 70-hour work period. Truckers also are limited to a 14-hour workday and no more than 11 hours of driving in a single day.

Rest areas testing the system are the Big Spunk Rest Area near Albany, Enfield near Monticello and Elm Creek in Maple Grove.

Cameras scan the lot to determine how many truck spots are open. The information is sent to a computer, which relays it to electronic signs, the MnDOT website and directly to truckers whose cabs are wired to receive it.

The system has worked at 95 percent accuracy since it went live in April, said Truck Availability Parking System (TAPS) project manager John Tompkins.

With information about the number of spots available, truckers can decide whether to pull off or proceed to the next rest area.

“We don’t want trucks parking on exit or entrance ramps because they are not safe,” he said. “We want to provide safe parking and this is one way of doing this.”

Like other states, Minnesota has a shortage of long-term parking for commercial motor vehicles. The problem is expected to get worse as the trucking industry rebounds from the recent recession.

Minnesota, which got a $2 million grant, is one of several states to get federal money to study the issue. Similar pilot projects are underway along the busy I-95 corridor on the East Coast as well as in Florida, California, Oregon, Utah, Tennessee and Pennsylvania.

The goal is to find a system that will work nationwide, Tompkins said.

Data from 2012 shows there were 317,000 crashes nationwide involving large trucks, or 868 a day. Truck crashes led to 3,921 deaths, or an average of 11 a day.

In its 2006 Large Truck Crash Causation Study, the U.S. Department of Transportation’s Federal Motor Carrier Safety Administration found fatigue to be a leading factor in truck crashes.

That played out on a New Jersey expressway in June when a sleep-deprived Wal-Mart truck driver slammed into a van, seriously injuring comedian Tracy Morgan and killing one person. Prosecutors said the driver had not slept in the 24 hours before the crash.

Tompkins said TAPS might be most valuable in the 6 to 9 p.m. time frame, the hours when truckers are deciding when and where to stop.

“It creates anxiety for drivers as the end of their work period draws near,” said John Hausladen, president of Minnesota Trucking Association. “Drivers pull off and circle around and hope there is space. If they discover there is not, now they’ve lost time and burned more fuel. We support this. To be able to make good decisions to stop for the night is important.”