One-way traffic

One-way traffic (or uni-directional traffic) is traffic that moves in a single direction. A one-way street is a street either facilitating only one-way traffic, or designed to direct vehicles to move in one direction. One-way streets typically result in higher traffic flow as drivers don't have to deal with oncoming traffic nor turns through oncoming traffic. Residents may dislike one-way streets due to the circuitous route required to get to a specific destination and the potential for higher speeds affecting pedestrian safety. Some studies even challenge the original motivation for one-way streets in that the circuitous routes negate the higher speeds.

Signage

General signs

Signs are posted showing which direction the vehicles can move in: commonly an upward arrow, or on a T junction where the main road is one-way, an arrow to the left or right. At the end of the street through which vehicles may not enter, a prohibitory traffic sign "Do Not Enter", "Wrong Way", or "No Entry" sign is posted, e.g. with that text, or a round red sign with a white horizontal bar. Sometimes one portion of a street is one-way, another portion two-way. An advantage of one-way streets is that drivers do not have to watch for vehicles coming in the opposite direction on this type of street.