Traffic Light

Traffic lights are an indispensable facility in modern traffic management. They direct vehicles and pedestrians to pass in an orderly manner through light signals to ensure road safety and efficiency. The following is a detailed introduction:

I. Basic composition and color meaning

1. Red light

Meaning: No passage.

Function: Vehicles must wait behind the stop line, and pedestrians are not allowed to cross the road (right turns are allowed in some countries, but specific rules must be followed).

2. Yellow light (Yellow/Amber)**

Meaning: Warning transition signal.

Function: Indicates that the red light is about to turn on and the vehicle should stop passing; if it has passed the stop line, it can continue to pass. In some countries, flashing yellow lights indicate cautious passage.

3. Green light

Meaning: Passage is allowed.

Function: Vehicles and pedestrians can pass through the intersection under the premise of ensuring safety, but they must give way to vehicles or pedestrians from other directions that have entered the intersection.

2. Common types of traffic lights

1. Motor vehicle traffic lights

Red, yellow and green, usually circular or arrow lights, control vehicles to go straight, turn left or turn right.

2. Pedestrian traffic lights

Red and green, often with standing/walking human figures or text (such as "Wait"/"Walk").

Some countries have countdown timers to indicate the remaining travel time.

3. Arrow direction lights

Green arrows allow passage in a specific direction, and red arrows prohibit passage in that direction.

4. Special traffic lights

Bus-only lights: control the passage of buses or priority vehicles.

Railway crossing lights: Flashing red lights indicate that a train is approaching and must stop immediately.

3. Arrangement of traffic lights

Vertical arrangement: red lights on top, green lights on the bottom, and yellow lights in the middle (common in North America, China, etc.).

Horizontal arrangement: red lights on the left, green lights on the right, and yellow lights in the middle (such as Japan and some European countries).

4. Intelligent traffic signal system

Modern traffic lights may be equipped with the following technologies:

Adaptive control: adjust the signal duration in real time through sensors or cameras to relieve congestion.

Networking system: Link with smart city platform to optimize regional traffic flow.

Emergency priority: provide green light priority for ambulances, fire trucks, etc.

5. Differences in traffic rules (international attention)

China: No right turn at red light (unless there is a separate arrow green light).

USA: Right turn is allowed at red light (some states require stopping and observing first).

-Europe: Flashing yellow light may mean "give way" or night mode.

6. Safety tips

Don't run yellow lights: it is easy to cause intersection rush accidents.

Green lights also need to be observed: be alert to violations of vehicles or pedestrians in other directions.

Pedestrian button: Some countries require manual button to trigger green light.

Correctly understanding and complying with traffic light rules is an important guarantee for safe travel!