Solid Double Yellow Line on Highways

Lane discipline and overtaking

Overtaking, usually called "passing", is legal on all four or more lane roads and on most two-lane roads with sufficient sight distance. On two-lane roads, one must pass to the left of the overtaken vehicle unless that vehicle is preparing to make a left turn, in which case the vehicle must be passed on the right. Passing on the left means that the overtaking vehicle must enter the oncoming lane. This should only be done in a legal passing zone, designated by either a dashed yellow centerline (indicating that passing is legal in both directions) or a solid line paired with a dashed line (indicating that passing is only legal for traffic adjacent to the broken line). A solid double yellow line indicated that passing is illegal in both directions. In some states, it is not against the law to overtake vehicles in the presence of solid yellow lines if it is safe to do so. For example, Vermont state law also allows passing across the double yellow line when no traffic is on the opposing side; however, one must pass quickly and return to the proper side.^[3]However, this is unusual as most states have a ban on crossing a double yellow line except when turning, or when pedestrians, bicycles, or other obstructions in the road make it necessary. Overtaking another vehicle across a solid yellow line is usually considered a serious traffic violation in most states.^[4]

On roads with four or more lanes (including divided highways), vehicles may pass to the left or to the right of slower vehicles as long as the maneuver can be completed safely. However, most states either suggest or require that through traffic stay to the right except to pass.^[5] The Manual on Uniform Traffic Control Devicesincludes several signage standards to inform drivers of proper lane discipline, including the "STAY RIGHT PASS LEFT" and "SLOWER TRAFFIC KEEP RIGHT" signs.^[6]