Truck drivers passing through Minnesota who need a safe place to pull off the road will be getting help from the Minnesota Department of Transportation, which last week began installing new technology that will let them know in real time if rest areas still have parking spaces available.

MnDOT is rolling out the Regional Truck Parking Information and Management System at seven rest areas on the high-volume freight corridors of Interstates 94 and 35, routes on which truckers who have reached their time limit and need to quit driving often have trouble finding places to park.

At least seven other states are developing similar systems with the goal of creating an interstate network that should be operational by January 2019. Minnesota's is expected to be running before that.

"Rest areas fill up at night and truckers often park on exit ramps, which are unauthorized spots," said MnDOT project manager Dan Rowe. "This is a safety concern and when we provide safe parking for truckers, we also save lives by getting fatigued drivers off the road."

MnDOT is putting sensors about the size of a hockey puck under the pavement that can detect the presence of a truck. That information is sent to the Regional Transportation Management Center in Roseville and then relayed to changeable message signs along the highway that display the number of available truck parking spaces at rest areas.

Parking information also is displayed on the agency's trucker 511 highway information page and forwarded to trucking company dispatch centers.

"We are excited by the deployment of this technology," said John Hausladen, president of the Minnesota Trucking Association. "One of the biggest concerns drivers have at the end of the day is where they can park safely.

This will allow truckers to "plan their trip and see if space is waiting when they get there," he said.

The system is an outgrowth of a pilot project that Minnesota began working on after the passage of Jason's Law in 2012. The federal law named for trucker Jason Rivenburg, who was shot twice and killed in a 2009 robbery for $7 cash as he cleaned his dashboard at an abandoned gas station in South Carolina, required the Federal Highway Administration (FHWA) to address the problem of long-term parking for truckers.

Federal regulations limit truckers to a 14-hour workday and no more than 11 hours of driving in a single day and 70 in a week. A study by the FHWA survey found 75 percent of drivers reported consistent trouble finding safe parking when they must rest. Minnesota was identified as one of the states with the most severe parking problems. The parking crunch is most acute on weekday evenings and early morning hours, Hausladen said.

In testing this winter at the Elm Creek Rest Area in Maple Grove, MnDOT has learned that placing two pucks in each parking spot "is better than one," Rowe said. With long stalls, if a truck pulls in but stops short of the magnetometer, it may not be detected. With two placed in each of the 21 stalls, the sensors have been more likely to detect a truck. So far the data has been "very accurate," he said.

The technology will be deployed on eastbound I-94 rest areas near Alexandria, Albany, Enfield and Maple Grove, on westbound I-94 at the St. Croix River, southbound I-35 in Forest Lake and northbound I-35 near the Northfield exit.

A $25 million federal grant will cover most of the costs for the project, which is also being implemented in Iowa, Indiana, Kansas, Kentucky, Michigan, Ohio and Wisconsin. Minnesota will get $1.4 million in grant money and MnDOT put in $177,500.

Tim Harlow • 612-673-7768