| +/- highway=traffic_signals
A traffic signal for regulating circulation.
Traffic signals, also known as traffic lights, traffic lamps, signal lights and stop lights are signalling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic.
Traffic signals for cars
|highway||traffic_signals||Required. Indicates traffic signals for cars.|
|ref||*||Reference number or code.|
|traffic_signals||*||Additionally used to indicate special types of traffic signals.|
|traffic_signals:direction||forward / backward||Applies only when tagging traffic signals separately for each crossroad. Tells whether this particular signal affects cars moving in the same direction as the way (=forward) or in the opposite direction (=backward).|
Traffic signals for pedestrians
Add the following tags in addition to highway=traffic_signals for pedestrian crossings if the entire crossing is represented by a single node, or to separate highway=crossing nodes if the pedestrian crossings are tagged on their own (strongly recommended).
|crossing||traffic_signals||Required. Indicates traffic signals for pedestrians.|
|button_operated||yes / no||Used to indicate that the traffic signals need to be activated by pressing a button.|
|traffic_signals:sound||yes / no||Whether there are sound signals for visually impaired people.|
|traffic_signals:vibration||yes / no||Whether there are vibrating signals for visually impaired and deaf people.|
|traffic_signals:arrow||yes / no||Whether there is a tactile arrow available at the traffic light pole to indicate for blind persons in which direction the pedestrian crossing leads.|
|traffic_signals:minimap||yes / no||Whether there is a small tactile map at the traffic light pole to indicate the crossing layout for blind persons.|
|traffic_signals:floor_vibration||yes / no||Whether there is a device that lets the floor vibrate at walk signal. Often used near homes of deaf-blind persons.|
How to map
Because traffic signals can affect routing decisions, it is important that they are attached to the ways to which they apply.
For simple intersections, just tag the intersection node. The same applies to traffic signals which are not part of any intersection, e.g. before tunnels.
Consider the following intersection:
The horizontal ways are actually one large way, represented by two one-way streets. The problem now is that traffic signals should ideally be applied to each way exactly once. As of now, there is no well established convention on how this problem should be ideally solved, but possible taggings which are currently in use are listed below.
Further discussion is welcome on the discussion page.
Tag all crossings
Add traffic signals to the common nodes in the junction. This will create two separate traffic signals for the vertical way. It is up to the routing software to count nearby signals as one for timing purposes. Many junctions are tagged this way due to simplicity.
Tag all incoming ways
Instead of putting a traffic signal on each crossing, put a traffic signal on all incoming ways of a junction. Traffic signals added to dual-ways need to be tagged with either traffic_signals:direction=forward or traffic_signals:direction=backward to indicate the affected direction. In the given example this applies to the vertical way only, as the horizontal way is mapped with one-ways anyhow.
Tag all incoming one-ways
As before, put a traffic signal on all incoming ways of a junction, but split each incoming dual-way into two separate one-ways before. This avoids usage of the traffic_signals:direction=* tag, but might only be appropiate if each connected way should actually be represented as two separate one-ways (you probably shouldn't split a dual-way into two one-ways just because of traffic signals).
|Pedestrian traffic signals with sound|
- Traffic light on Wikipedia
- Relation:enforcement : to define an enforcement traffic signals ;
- Look and Listen Map - Blindmap
- eWorld+SUMO traffic simulation
- Proposed features/Set of Traffic Signals
Related terms: <traffic signals>