A traffic light is a signal used to regulate traffic flow and ensure road safety . Traffic lights provide visual signals using red, amber, and green light and are used at roads, intersections, railway crossings, and pedestrian crossings .
1. Characteristics of a traffic light
✅ Three-color system → Red, Orange (Yellow) and Green .
✅ Fixed time interval or dynamically controlled → Can work with sensors, timers or traffic management systems .
✅ LED technology or halogen lamps → Modern traffic lights use energy-efficient LEDs .
✅ Multiple variants → Cars, cyclists, pedestrians, public transport and level crossings .
✅ International standardization → Colors and signals are comparable worldwide.
2. Meaning of the colors of traffic lights
| Colour | Meaning | Action |
|---|---|---|
| 🔴 Red | Stop | Do not proceed |
| 🟠 Orange (Yellow) | Please note, stop if possible | Prepare to stop |
| 🟢 Green | Free passage | Continue as safe |
Additional variants:
🚦 Flashing orange → Give priority (in case of faults or night-time operation).
🚴 Bicycle traffic lights → Especially for cyclists, often with a bicycle symbol.
🚶 Pedestrian lights → Red/green figure for pedestrian crossings.
3. Types of traffic lights
| Type of traffic light | Application |
|---|---|
| Car traffic lights | Regulates car traffic at intersections. |
| Bicycle traffic lights | Specially for cyclists, often with a bicycle symbol. |
| Pedestrian lights | Red/green symbol for pedestrian crossings. |
| Public transport traffic lights | Special lights for buses and trams. |
| Level crossings | Flashing red lights at railways. |
| Dynamic traffic lights | Adjusts the light phase based on traffic density. |
4. How do traffic lights work?
🚦 Fixed timing → Based on a preset cycle without traffic detection.
🎯 Dynamic control → Traffic lights adapt based on sensors, cameras or traffic models .
📡 Smart Traffic Lights (SRT) → Connected to central traffic management systems to reduce traffic jams .
5. Special traffic lights
🚥 Intelligent traffic lights → Respond to traffic congestion and reduce waiting times.
🚛 Truck traffic lights → Extra large for freight traffic.
🔴 Flashing lights at bridges and tunnels → Warn of impending closures.
💡 In short:
A traffic light is a signal system used to guide vehicles and pedestrians safely through traffic . Modern systems utilize smart technology to improve traffic flow and reduce congestion.