MnDOT turns to digital signs to warn drivers about snowplows

The Minnesota Department of Transportation is testing technology that uses digital sign boards to warn motorists when they are approaching snowplows or slow-moving maintenance trucks, a pilot project that could pave the way for the agency to deliver audio alerts directly to drivers' smartphones.

Statewide, plows are involved in more than 100 crashes a year, with most of them occurring when plows are rear-ended by drivers who don't see them. MnDOT officials said they hope signs warning of plows or maintenance vehicles immediately ahead will get motorists to slow down, move over and stay safe.

"I'm excited about this," said Jed Falgren, MnDOT's state director for Transportation System Management and Operations. "It has the potential to make a difference for travelers and keep plows safe."

Most of MnDOT's 800 plows are already equipped with technology that records their location, speed and direction of travel. That information can now be beamed to electronic digital signs on bridge decks or on the side of the road.

When a plow passes by, it sends a signal to the sign, triggering it to show a message telling motorists to use caution because a plow or other type of vehicle working on the road is ahead.

Warning messages will stay on as long as the plow is in the area and can "talk" to the sign. That is usually just a few minutes. Messages will shut off automatically when plows are out of range or if the plow turns off the road or reverses direction, Falgren said.

If a sign is already displaying a message — such as one of MnDOT's Monday safety messages — when a plow passes by, information alerting drivers about the plow will preempt it.

Crashes happen most often when plows obscured in a snow cloud and traveling at slow speeds are hit from behind, said MnDOT spokesman Mike Dougherty. The signs are another tool "to boost safety" and "to stop rear-end collisions," he said.

MnDOT is running the pilot this winter along Interstate 35 using a dozen signs between Lakeville and the Iowa border. But the test could be expanded to other routes such as Interstate 94 between the Twin Cities and Moorhead and on Hwy. 52 between the Twin Cities and Rochester before the end of the snow season, Falgren said.

It could also be used during summer months to warn drivers when crews are repairing cable median barriers or mowing.

The agency has bigger ambitions for the future, namely how to directly connect with motorists.

With a large number of drivers owning smartphones, Falgren said MnDOT is looking to develop an app that would allow drivers to share their location. Drivers who turn the app on would get a message when their mobile phone comes near a plow.

"It would be 15 to 60 seconds before you encounter the plow," Falgren said. "Not too late, so you can take corrective action."

MnDOT is still working on what type of message that would be. But most likely, Falgren said, it would be an audio message so drivers would not be distracted driving by reading or picking up their phones.

"We want to solve a safety problem, not create a safety problem," he said.

Volunteers to help test the app could be recruited as soon as late summer, Falgren said.

The sign-testing project is being conducted as MnDOT prepares for the arrival of connected and automated vehicles and is researching how advancing technology can improve safety.

"This is a really great tool that takes us on the next step on connected and automated vehicles," Falgren said. "This is taking current technology and finding more and better usages for it."

Tim Harlow • 612-673-7768