Traffic light sensors at many Irish junctions don’t detect bicycles says campaign

Sensors at many junctions in Irish cities are not detecting bicycles, according to the Galway Cycling Campaign.

It said that while it “cautiously welcome the introduction of on-the-spot fines” it claims that the timing is not right because “our roads are not yet ready for implementing the running a red light offence”.

Shane Foran, Galway Cycling Campaign’s technical specialist, said: “For example, I am cycling and I stop at the stop line at a junction. The lights do not detect me, so they stay red, and a queue forms behind me. If I go beyond the stop line, which is technically an offence, and beckon the driver behind me to move forward to activate the sensor, only then will the lights change.”

He added: “If I was cycling into town at night when it was a bit quieter, and there were no cars behind me at this junction, I would be left waiting there in vain. The lights would stay red indefinitely. I would argue that in effect, several generations of Irish roads engineers have been training Irish cyclists to ignore red traffic lights.”

The Galway Cycling Campaign said that the situation is “a failure on behalf of roads authorities to comply with the law” which states that a road authority shall consider the needs of all road users.  It said it is calling on the minister for transport Paschal Donohue to issue a direction ordering that all traffic signals change for cyclists.

“This flaw in the system is easily remedied. Timers at traffic lights could be used instead or else more appropriate sensor systems,” said Foran.


  1. Most light sensors are induction sensors meaning that they detect moving metal. Chiefly steel, but other metals will trigger them. The sensor needs to pass a threshold to activate. So a car moving at all will trigger it because it is so large. However a bicycle moving slowly may not trigger it. A bicycle moving quickly will trigger it (mostly). But that means that cyclist run the risk of overshooting the white line. My bike is an old steel frame bike and it has struggled to set off lights in the past. The users with the biggest problems will the anyone with the funds to own a carbon bike. These bikes essentially don’t exist to metal detecting sensors.

  2. Interesting. The light filter to turn right into Greenfield Park at the RTE junction, Stillorgan Road, Dublin doesn’t detect my steel bike. I have tried everything: fast, slow, weaving…. There should be some sort of register to record these problems for eventual remedy. I’ve had moderate success with the Dublin City Council ‘repair a road or footpath’ online report facility. Perhaps they could extend it to traffic lights.

  3. I’ve had this happen twice to me in Dublin: once at the junction coming from Coolmine Sports Centre onto the Snugborough Road (stood waiting through a whole sequence till a car came up behind me and, lo and behold, there’s the green light) and one time, believe it or not, at the east end of the contraflow bicycle lane in Blackrock village! If the lights for cycles don’t even detect the very vehicles they’re intended for…

  4. Yes, I’ve experienced this too, traveling from Lansdowne Road to Pembroke Road. Usually there are cars at the junction, so the sensor is activated. However at quiet times, with no cars heading my way, the only option is to run the red light.
    I don’t have a problem with the new FCN’s, but this type of issue needs to be looked at. Cycommuter makes a good point, that there should be a way to flag it to the council. This will at least put it on record, and depending on the circumstances, might give a basis for an appeal.

  5. According to the type of frame you have on your bike is a lot less critical than how you position your wheel over the induction wire. I have tried this at the exit from the work car park and at the traffic lights at the Stephens Green/Leeson St junction and aluminum wheels work fine on both carbon and aluminium frames. Carbon wheels might be problematic but I doubt if I will be riding those around town any time soon.
    Like Cycommuter I have had a good response when reporting potholes directly on the DCC website. I reported the issue with the Stephens Green lights on Fix My Street (or similar) and got no response despite a follow up complaint.


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