Bike doesn't trigger traffic lights!


Legendary Member
Anybody else noticed that bicycles sometimes don't get picked up by the induction loop buried in the road to trigger the lights?

My evening quickie goes out to a big junction on the A59 and takes a little traffic lane that's only used occasionally by people making a rather illogical U turn. The rest of the traffic lights go through their sequence, the traffic across my route stops but I don't get a green. So - *shudder* - I ride through on red! This is the carbon road bike; the metal MTB sometimes gets picked up but not always; it gets embarrassing sitting waiting for a car to come along and rescue you.


These lights here are the same. Much as I hate doing it, I cross with the peds :becool: as there's only a few cars a day use that piece of road. :wacko:


My Armchair
I have 2 or 3 sets that don't pick me up on the commute,you have to treat them as out of order or wait for a vehicle to trigger them,but at 5am I could be waiting a while so go thru them when safe.
If you're not comfortable doing that then get off and push it thru.


New Member
There are a set on a fairly busy road on my commute that trigger a filter.

I sit at them looking backwards to see if a car will join me.

If it changes twice I have to go for it as the main lights change :becool: otherwise I should imagine I could be sitting (standing) there a while.


Legendary Member
Ooh Norm that looks twee! Is that the route you take when you pop up for tea with Queenie?
The set near me is the same from one direction - a friend of mine complained to the council about the same lights about 20years ago - he was advised to get off his bike and lay it down over the induction loops - with an additional advisory that it was probable that his bike was made of "alloy" and would not be detected - we actually worked for a different highways department of the same council - we had a good laugh - I am at present waiting for a response to my recent complaint 20+ years on - I know quite a lot of the team so I am waiting to see what is said.

At the moment I just treat it as being out of order - when it is safe to proceed cross in a cautious manner


Globalti said:
Ooh Norm that looks twee! Is that the route you take when you pop up for tea with Queenie?
Not quite Queenie (although she does indeed live very close to that junction) but I have met up with Hotmetal a few times near there. :biggrin:

Mille said:
More Captain Redbeard "You have a woman's hands" Rum than Melchett.

But that Queenie, eh, phwoar, eh... :laugh:


The loops work like metal detectors, so non-ferrous bikes are OK, and carbon bikes with alloy wheels should also be OK. You'll get detected best if your bike is positioned along the long edge of the loop rather than across the middle.
If the lights are a problem, I'd suggest complaining to the council about them. They can adjust the sensitivity up enough to detect any bike, but if they turn it up too far they start detecting traffic on the other side of the road. There are some lights near me that keep switching from detecting to not detecting.

The detectors on some lights are microwave doppler, and detect the movement of approaching traffic, so if you roll up to the light too slowly you may get registered as a pedestrian. The lights have small square boxes on top. There may also be old unused loops in the road.


I know what you are saying, Andrew, but the one in my link is in a mostly-pedestrianised area which has a handful of cars daily, and it is on the bridge between Windsor and Eton so it gets a gazillion tourists walking over it. I guess it would be almost impossible to set it to set the sensitivity to pick up a chap on a bike and not be triggered by several hundred kilos of tourist.

Mille said:
Ah yes

Blackadder, Blackadder. He saw the ocean's foam.
Blackadder, Blackadder. He should have stayed at home.
Blackadder, Blackadder. He heard the new world's call.
Blackadder, Blackadder. Discovered bugger-all.

Good grief!
Bikes - check
Motorbikes - check
Ability to quote Slack blAdder - check

I think I've just found the perfect woman! :biggrin:

John the Monkey

Frivolous Cyclist
Oddly enough I was chatting to a chap on an Alu hybrid about this today - my LHT (which admittedly, is A LOT of metal) seems to trigger lights with no problems.
I have only one set of traffic-controlled lights on my commute, and mostly they seem to work fine. But then my commuter's a steel bike :becool:. However my wife rides an alloy hybrid past the same lights and she doesn't have a problem either. I think it may depend on how the sensor was installed.

This is an age-old problem and for me it goes back to the bad good old days of pressure switches set into the road surface, common when I was a kid. As a cyclist, especially as a small child, I hadn't a prayer of working those. Time to be a RLJer - or get off and walk!

But I believe that some more modern installations work from cameras rather than embedded sensors, with some sort of motion-sensing software. How they can distinguish between cyclists and pedestrians I don't know, but I have passed such set-ups at road works and they appear to work OK.
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