There used to be four tunnels underneath West Jefferson Avenue and Schaefer Road in River Rouge. They were pedestrian walkways. Back in the days they were built and used, the amount of traffic, autos and trucks, on those thoroughfares was immense, particularly during the shift changes at factories, and there were dozens of factories. As kids, we walked to and from school during those shifts, so using the tunnels was almost a necessity at times. Most people avoided driving the streets during those hours if they weren't part of the rush hour, usually walking 'up the street' if they had business or shopping to transact.