DES MOINES, Iowa (AP) – The Iowa Transportation Department is testing a new system that could help motorists drive more safely on icy roadways. Des Moines television station KCCI says the testing is underway on an 11-mile stretch of Interstate 35 north of Des Moines. During and after storms, some drivers go too fast, some too slow.

The system being tested comes up with a limit that, if observed, would smooth out traffic flow and make travel safer. The system includes sensors that use lasers to detect the ice, snow or slush on the pavement. Engineer Willy Sorenson says the system uses the data to determine what he calls an “advised” lower speed limit. That safer speed limit is sent to four digital speed limit signs along the roadway.