Can someone explain how to connect an overpass to the ground level? I can get roads of various heights, but I can never seem to connect them to the ground level. I select Overpass 2, draw the test piece, then draw my section of road where I want it. From there, I switch back down to default, but it doesn't snap to the upper road. I've ever tried taking down a step from Overpass 2 to Overpass 1 and then to the default level and still nada.