trafikklyssignal

Trafikklyssignal, commonly called a traffic light, is a signaling device used to regulate the movement of road users at intersections, pedestrian crossings and other points where conflicting traffic flows meet. Its main purpose is to reduce crashes and improve the efficiency of transportation by providing clear, predictable instructions.

Most traffic signals use three standard colors: red, amber (yellow) and green. Red means stop and wait until the signal changes. Green means proceed, if the way is clear. Amber indicates that the signal will change to red soon and that drivers should prepare to stop. In many regions, a red-yellow phase appears before green to warn of an imminent change. Some signals also include protected turning arrows, which allow turning movements to occur in specific directions even when the main signal is red.

Operation and control of trafikklyssignal can be fixed-time or actuated. Fixed-time signals follow a preset cycle, while actuated signals adjust timing based on traffic demand detected by sensors such as inductive loops, cameras or radar. Modern networks may use centralized controllers, optimization algorithms, and, in some cases, priority for public transport, emergency vehicles, or platoons of freight traffic.

Pedestrian signals work in tandem with vehicle signals and often include a walking figure or countdown timers to indicate how long pedestrians have to cross. Accessibility features, such as audible cues or tactile indicators, are included in many systems to assist visually impaired users.

If a trafikklyssignal fails, the standard safety procedure is to treat the intersection as a four-way or all-way stop, proceeding with caution according to right-of-way rules.