A four-lane highway is a type of road designed to accommodate four lanes of traffic, typically two lanes in each direction. These highways are built to facilitate faster travel and improve safety by reducing congestion. They often feature a median or barrier separating the opposing lanes, which helps prevent head-on collisions. Four-lane highways are commonly found in urban and suburban areas, connecting cities and towns. They may include features such as on-ramps and off-ramps for easier access to local roads. Examples of four-lane highways include interstate highways and state routes, which play a crucial role in transportation networks.