Traffic light maintenance

Report a traffic light issue

Traffic light issues can include:

•  phasing problems with the lights — lights changing too quickly or not giving enough time to cross or turn
• damage caused by an accident or by vandalism
• faulty lamps
• buttons or other equipment not working.

How traffic light sensors work

Traffic lights in Auckland use sensors in the road and on poles to help control traffic. These sensors find cars and change the lights as needed.
 
If no cars are waiting on a side street, the green light there can be skipped or made shorter. This gives more time to busy roads.

Occasionally, when a sensor fails, the system sets a default signal to act as if a vehicle or cyclist is waiting. This makes the lights run through a full cycle, which can cause minor delays.
 
The sensors send information to AT’s control system. This system can change the lights during busy times or emergencies. This helps cut delays and keeps traffic moving.

Underground vehicle detectors

Vehicle detectors are installed under the road surface close to the stop line on the approach to the intersection. The detector loops register the presence of vehicles by the metal of the vehicle bodies.

The detector loops can detect the presence of moving vehicles, stopped vehicles and queue length. Based on this the detector registers a demand for a green signal or extends a green signal.

The detectors might not detect vehicles if the sensors are damaged or if vehicles are stopped too far from the detectors.

Bicycle detectors

Some intersections have special areas in front of the traffic queue where cyclists can stop — the area is often coloured green and sometimes marked with a bicycle stencil.

These cycle boxes have underground or sometimes above-ground bicycle detectors that register the presence of cyclists.  

'B' bus lights at traffic signals

'B' bus lights at traffic signals give priority to buses. This allows them to drive through an intersection, usually into a bus lane, while other traffic is stopped at a red light.

The underground detectors for bus lights are set up to detect buses only. They do not respond to the presence of cars.

Ramp signals

Ramp signals (also known as ramp metering) are the traffic signals at motorway on-ramps. Ramp signals manage the rate at which vehicles move down the ramp and onto the motorway.

Ramp signal issues