Freezing rain is the version of winter Michigan saves for the parking lots. It arrives overnight, ahead of the snow, and turns flat blacktop into something nobody should try to walk across. D&P Services, Inc. reads those forecasts and goes out early — plowing when there is depth to push, salting and treating when there isn't, keeping drives and lots open through a storm instead of after it. By the time the first cars swing in off Six Mile, the surface is dark and gritty and safe underfoot. Northville and the working corridors around it sit on that route.