Red traffic light

How to read it

The MUTCD, the national standard for U.S. traffic signals, says traffic facing a steady circular red stops at the marked stop line, or before the crosswalk where there is no line, or before the intersection where there is neither, and stays stopped until a signal to go is shown. It makes one exception. Unless a sign prohibits it or a red arrow is lit, traffic may turn right after stopping, or turn left from one one-way street into another, under the same rules as after a stop sign. Pedestrians facing a red light, where there is no pedestrian signal, do not enter the roadway. California’s handbook puts the meaning in one word: a red traffic signal light means STOP. This page describes the national standard and isn’t legal advice; the rules at a signal are set by state law and vary from state to state.

Also searched as: red light, red signal, steady red light.

Can you turn right on a red light?

Under the MUTCD, yes, after stopping, unless a NO TURN ON RED sign is posted or a red arrow is lit. Each state writes the rule into its own law, and the manuals word it differently. California’s handbook allows a right turn at a red light where no sign forbids it, after stopping at the stop or limit line and yielding to pedestrians. Pennsylvania’s and Florida’s allow the right turn and also a left turn from a one-way street onto another one-way street, after stopping and yielding to pedestrians and other traffic. Oregon’s manual puts it by the road being entered: onto a two-way road the turn on red is right only, and onto a one-way road it may be right or left in the direction of travel. It adds that a police officer, as well as a sign, can forbid it.

Why red is on top

The MUTCD requires every red light in a vertical signal to sit above the yellow and green ones, and in a horizontal signal to sit to the left of them. Pennsylvania’s manual teaches drivers the same order: red on top or on the left, green on the bottom or on the right. The colours are older than the national manual. The FHWA’s history of the MUTCD dates the first electric traffic signal to Cleveland in 1914 and the first three-colour signal to Detroit in 1920; the first MUTCD was published in 1935.

Red light, red arrow or flashing red

A steady red arrow stops only the turn it points to, and the MUTCD allows no turn on it unless a sign permits one. A flashing red light has the meaning of a stop sign: a full stop, after which traffic may proceed under stop-sign rules.