 A road with two lanes of traffic moving in opposite directions is specifically called a two-lane road.In keeping with the U.S. Department of Transportation's "Manual on Uniform Traffic Control Devices" (MUTCD), since the early 1970s all numbered highways in the U.S. are striped by color to show the direction of traffic flow.Two-way undivided roads have an amber center line (and, if there are baseline shoulder stripes, they are solid white on both sides).