Traffic lights and signal-controlled crossings

What traffic lights control

Traffic lights are light signals that organise movements where roads meet or pedestrians cross. In South Africa they are also commonly called robots. They allow conflicting streams of traffic to move at different times instead of arriving in the same space together.

You may see them at intersections, junctions, pedestrian crossings and controlled road sections. Look for the signal facing your approach and, where provided, the one applying to your particular lane or intended movement. A light facing cross-traffic is not your signal.

The familiar vertical arrangement places red above amber and green. Position, shape and direction matter as well as colour: arrows, pedestrian figures and overhead lane signals have specific meanings. The diagram introduces the ordinary vehicle signal; later sections explain the differences.

Key idea: Use the signal facing your approach and intended movement.

Red: stop before the line

A steady red vehicle signal requires you to stop. Approach at a speed that lets you brake smoothly and bring the vehicle to a standstill before the stop line. Keep the pedestrian crossing and junction clear.

A stop line is the transverse road marking identifying the stopping position. Do not stop with the front of the vehicle over it or inside the crossing. Once stopped, wait for a signal authorising your movement, unless a traffic officer directs you otherwise.

Do not interpret an ordinary red disc as permission to turn left after stopping. A specific flashing red left arrow is a different signal, explained below. An empty intersection, pressure from a following driver or a short intended turn does not cancel an ordinary red light.

Key idea: Ordinary red means stop and wait; it is not a general turn-on-red permission.

Amber: decide whether you can stop safely

A steady amber signal warns that the permitted phase is ending and requires you to stop, except where you cannot do so safely. It is not an instruction to speed up.

While approaching, check traffic behind, the distance to the stop line, road grip and your speed. If you can stop safely before the line, stop. If you are so close that a stop cannot be made safely, continue cautiously without accelerating to beat the light.

Planning starts before amber appears. Slowing appropriately on approach and leaving a suitable following gap makes the decision less abrupt. Do not copy the vehicle ahead: it may reach the line earlier and face a different stopping decision. A steady amber arrow requires you to stop and wait for the arrow phase allowing your movement.

Key idea: Stop for amber when you can do so safely. Never race the changing light.

Green: check before entering

A steady green signal permits movement if it is safe. It does not prove that the whole junction has become clear. Vehicles may still be completing an earlier movement, pedestrians may be crossing, and another driver may ignore a red signal.

Before moving, check your intended path and the space beyond the junction. If a queue blocks the exit, wait before the stop line rather than entering and stopping across cross-traffic or the pedestrian crossing. Check again when space becomes available.

If turning, observe the relevant arrow signals and any traffic or pedestrians with priority. Do not assume a general green disc gives a protected right turn across opposing traffic. Signal your intention, use a safe speed and enter only when your movement will not create a conflict.

Key idea: Green permits a safe movement; it does not remove observation or yielding duties.

Arrows and flashing signals

An arrow applies to the direction shown, not to every possible movement. The reference manual distinguishes a flashing green arrow giving right of way in that direction from a steady green arrow directing movement. Continue to check for pedestrians and unexpected traffic even during a permitted arrow phase.

A flashing red left arrow allows a left turn only after you have stopped and yielded to relevant traffic and pedestrians. It is not the same as an ordinary red disc. A flashing red vehicle signal at a junction requires a stop, followed by movement only when safe, as at a stop sign.

A flashing amber disc calls for a careful approach and yielding to pedestrians. Do not mistake it for a normal green phase. At a railway crossing, flashing red means a train is approaching: remain stopped until the light stops flashing and all other controls permit crossing. Do not apply the junction’s stop-then-proceed rule to railway warning lights.

Key idea: Read the shape, direction and flashing pattern, and recognise the setting.

Pedestrian figures and overhead lane controls

Pedestrian signals use a standing red figure and a walking green figure rather than ordinary vehicle discs. A red figure means pedestrians must not start crossing. If the red figure flashes, someone who has not entered the roadway must wait; someone already crossing should finish crossing promptly. Drivers must still allow them to clear safely.

Overhead lane signals apply to the lane beneath them. A steady green downward arrow indicates that the lane may be used. A red cross closes that lane; it may be used by traffic travelling in the opposite direction. A yellow sideways arrow warns that the lane closes ahead and directs you to leave in the indicated direction. Check for a safe gap before changing lanes.

If a traffic officer is directing the junction, follow the officer’s directions rather than a conflicting light. Watch for the signal addressed to your stream of traffic and wait if its meaning is uncertain.

Key idea: Pedestrian figures and lane signals control different road users and spaces.

Quick recap

• Red: stop and wait.
• Amber: stop unless you cannot stop safely.
• Green: proceed only if safe and the exit is clear.
• A flashing red railway warning is not permission to go after stopping.
• An officer’s directions override conflicting signals.