Ambulance, Police And Traffic Lights...

[daz1969]

When I was younger I was always told that ambulances and police were able to change traffic lights if they needed to get through in an emergency using some kind of device in the vehicle - was this ever true?

[bhg481]

The sensors are usually Doppler activated, which means it's the movement of the approaching vehicle which triggers them. They don't actually change the lights, just register the presence of an approaching vehicle, and the system works out which direction to give priority to.

[Gromit]

The pedestrian button at traffic light crossings also have no effect. The lights are parsed with each other, and the timing of their changing is determined by time of day and traffic volumes. A pedestrian pressing a button merely lights up the wait/don’t walk sign. It has no relevance to making the lights change quicker.

[theshedman]

When I used to drive fire trucks we were only allowed to drive through red traffic lights with caution and if we caused an accident then we could get charged. This was a while back so the law may have changed now.

[bhg481]

Gromit - wrong. The button registers the pedestrian's presence and the system balances the flow of traffic and decides when to change the lights. The crossing we use to go to our local supermarket usually changes immediately the button is pressed unless the traffic is heavy.

[Paul22118]

Emergency services have no ability to change traffic light to their favour in progress. Never have. They are legally permitted to cross the stop line on a carriageway against a red signal BUT if they do so they must accord due care and attention to other road users. If it goes pear shaped they could be liable for prosecution.

[barry1010]

Talking of pedestrian crossings, how many people know there is a knob underneath the control 'push button' panel that rotates so that blind people can feel when it is safe to cross.

[Old_Geezer]

Togo, your linked article says they don't react to flashing headlights. Merely that some systems can be confused by glare off headlights.

[Togo]

The newer hi tech ones do not, they have motion sensors above the top light. Induction loops are no good for the temperary ones, because of the time required for setting up and they are usualy under the road surface. The early sensors in the temp. ones did have light sensitive switches. They reacted to car headlights but were only fully effective between twilight and dusk.

[davebro]

Quite a lot of uninformed BS being dished here in my humble opinion!

[fbg40]

As a fireman for 25 years I have never been aware of such a thing ! However, I knew of a couple of Fire Stations who are on very busy main roads had a switch in the appliance room whereby if a call was received by operating this switch they could change a set of traffic lights outside the station to red to make it easier for them to get out. That was a long time ago mind you - it's probably changed by now. Perhaps there is someone who could prove me right or wrong as the case may be !!
FBG40

[barry1010]

FBG, this type of light is outside my local fire and ambulance stations https://www.hwfire.org.uk/news/01-03-2019-vehicles-ignore-wig-wag-lights-at-droitwich-fire-station

[fbg40]

Spot on Barry, just what I was talking about. Many thanks for posting.
FBG40