All states carry traffic laws that specifically require "obedience to traffic control signals and devices" (or similarly-worded language), meaning that drivers must observe and obey all traffic lights and stop signs when operating vehicles.

The most common traffic violation associated with traffic control signals and devices is "running" a red light or stop sign -- when a driver proceeds through an intersection:

• While a red light (or red turn arrow) is displayed on a traffic signal, or
• Without coming to a complete stop and following right-of-way requirements when a "stop" sign is posted.

Lawful Turns on Red Lights
State traffic laws related to traffic control devices usually allow drivers to execute a turn on a red light only in certain situations. For example, drivers may make a right turn at an intersection on a red light if there is no sign prohibiting "right on red", and if it is safe to do so under the circumstances. Similarly, some states allow a left turn on a red light when a driver is turning left from one one-way street onto another one-way street, and it is safe to turn under the traffic (vehicle and pedestrian) conditions.