From OpenStreetMap Wiki
|Gives details about the type or function of traffic signals.|
|Used on these elements|
|Status: in use|
|Tools for this tag|
Special traffic signals can be used as landmarks for navigation. For example, it may be easier to find a junction if you know there's a blinker there.
- traffic_signals=blinker: a 'mini' traffic signal, mounted in the normal place above the intersection, that flashes yellow if you have right-of-way and red if you must stop.
- traffic_signals=continuous_green: used for intersections where some lanes, separated from the controlled portion of the intersection, never have to stop and thus get a continuous green signal.
- traffic_signals=blink_mode: a normal traffic signal that can be activated, but is normally set to blink. It may be changed to normal operation in the future when an intersecting road is completed, or may be used only for special events.
- traffic_signals=emergency: a normal-looking traffic signal, often in front of a fire station, that turns red only to give emergency vehicles right-of-way. Color details may be different (e.g. flashing yellow instead of solid green in the bottom lens). Often a sign mounted next to the signals states 'emergency signal'.
- traffic_signals=bus_priority/tram_priority: normally off, but whenever a bus or a tram approaches, it first blinks yellow and then changes to red to allow or facilitate passage for the bus or tram
- traffic_signals=ramp_meter: a signal on an onramp to a motorway that limits traffic to promote free-flowing traffic. May be activated only during rush hours.
- traffic_signals=controller: not widely used. May overlap with man_made=street_cabinet + street_cabinet=traffic_control, or with widely used man_made=monitoring_station + monitoring:traffic=yes
traffic_signals=signal: because this was the default value in iD and many users still add it without thinking, it is impossible to add any meaning to this tag. If you're a mapper: don't use it. If you're a data consumer: don't try to interpret it.
Possible rendering: remove one of the three lenses from the normal traffic signal symbol.