The traffic system (lights) covers all fixed light and signal installations along and above the road that regulate traffic flow, provide information and ensure road safety. This article gives a clear overview of the key signal types, what they mean and the rules that apply.
Overview of signal types
| Signal type | Description | See also |
|---|---|---|
| Traffic lights | Three-colour signals for vehicles with red, amber and green | Traffic system (signs) |
| Pedestrian signals | Signals for people walking with green walk symbol and red hand | Traffic system (signs) |
| Flashing lights | Amber flashing beacons, often for temporary control | Traffic system (signs) |
| Lane control signals | Electronic signals over lanes showing allowed direction or closure | |
| Railway crossing signals | Red flashing signals at level crossings warning about trains | Traffic system (signs) |
| Road works lights | Amber flashing lights guiding traffic through work zones | Works warning and temporary signing |
| Public transport lights (white) | White signals showing when bus/tram may proceed in bus lanes | Traffic system, Trams in traffic |
How the signals regulate traffic
- Traffic lights control junctions and crossings by switching between phases
- Pedestrian signals work together with vehicle signals for safe crossing
- Flashing lights are common in temporary traffic control such as road works
- Lane control signals enable dynamic lane use to optimise flow
- Railway signals activate alarms and block the road when a train approaches
- Road works lights warn and guide safely through the work area
- Public transport lights prioritise buses and trams; for lane rules see Bus and HOV lanes
Priority and interaction
When signals, signs and markings conflict, follow this priority:
- Police directions
- Light and sound signals
- Traffic signs
- Road markings and general rules
See examples in Signals vs signs in traffic. For temporary setups, see Works warning and temporary signing.
Lane control signals in practice
Lane control is used on bridges, ring roads and tunnels. Key symbols and how to act:
| Symbol | Meaning | What to do |
|---|---|---|
| Red cross (X) | Lane closed | Change lane well before the gantry |
| Green arrow (↓) | Lane open | Continue in the current lane |
| White/yellow diagonal arrow (↘︎/↙︎) | Change lane in arrow direction | Mirrors, blind spot, indicate |
| Reduced speed limit | Variable limit | Adjust speed, see Variable speed limits |
Often combined with lane changes. Read more in Overtaking and lane changes and the difference between Motorway vs expressway. For tunnels, see Driving in tunnels.
General rules and recommendations
Duty to follow signals
All road users must follow fixed light and signal installations. Violations can lead to fines and penalty points.
Failure or outage
If a signal system fails, drive with extra care, reduce speed and yield as appropriate. See Handling emergencies.
Flashing amber and dark junctions
Flashing amber means the system does not regulate normally. Then follow signs and basic rules:
- Follow give-way/priority signs
- If dark with no signs, use the right‑hand rule; see Give-way rules in detail
- Reduce speed and expect unpredictability
Signal overview illustration
Further reading
- Traffic system (lights)
- Traffic system (signs)
- Traffic rules for special vehicles
- Signals vs signs in traffic
- Works warning and temporary signing
Frequently asked questions
Can I turn right on red?
No. In Norway it is not allowed to turn right on red unless a separate signal explicitly allows it. See Give-way rules in detail.
What should I do with flashing amber at a junction?
Follow signs and basic rules, and apply the right‑hand rule if no signs. Read Give-way and roundabouts.
How should I relate to pedestrian signals?
Green man applies to pedestrians. As a driver, always ensure no one is crossing before moving, even on green. See Pedestrian crossings and give‑way.
What do the white public transport signals mean?
They control public transport. Drivers follow normal traffic lights and signs. For lane rules, see Bus and HOV lanes.