A one-way street is a type of road where traffic is allowed to move in only one direction. This design helps to improve traffic flow and reduce the risk of accidents by preventing vehicles from coming head-to-head. Signs are typically posted at the beginning of the street to inform drivers of the one-way rule. In urban areas, one-way streets are often used to manage congestion and enhance safety. They can also facilitate easier navigation for drivers, as they eliminate the need to make turns against oncoming traffic. Cities like New York and San Francisco frequently utilize one-way streets in their layouts.