How bad is speeding in your area? Here’s how to request data from “speed feedback signs”

How bad is speeding in your area? Some road safety campaigners get speed guns to measure their local speed, but, if your street has “driver speed feedback signs”, then there is a way to find out without standing on the side of the road.

Councils install the speed feedback signs in an attempt to slow drivers down. These devices don’t just display the speed but also record the speed of motorists.

This data can be requested from your council using an Access to Information on the Environment (AIE) request, which works much like a Freedom of Information request. Here’s a template:

Dear Sir/Madam,

I am requesting the following under the Access to Information on the Environment (AIE) regulations, S.I. No. 133 of 2007:

  • The data generated from the speed display sign located at [insert name the location] for the timeframe between [insert timeframe depending on what you need].

My preferred method of receiving the information by email to this email address (insert your email adresss).

Please note: The Commissioner for Environmental Information has already ruled that speed and speed restrictions are falls within the definition of “environmental information” in the AIE Regulations. The ruling can be found here:


[your name etc]

For Access to Information on the Environment requests, you can search your local council’s website, but you sometimes will not find a separate address — if that is the case, search for the FOI email address and send it to that.

Your council may try to say that they do not have the data, so they will not release it. Unlike a normal Freedom of Information request, which has to be of an existing document or record, authorities are obligated to compile data that they have already collected for an AIE request.

This might take some time. In my case, the contractor who maintains the signs had to visit the signs from which I requested the data.

When I requested, I received this data from Mayo County Council. It was split into segments because of the timeframe I asked for. Your council might present the data differently, but the terms should be the same terms.

Just a few notes: Depending on the way the radar on the sign is set up, the data may include bicycles, which lowers the average if there’s a significant number of bicycles.

Vmax = the highest speed. V85 = refers to the 98th% percentile speed, which is sometimes used to say there is little/no speeding issues — see Not Just Bike’s video on why the 98th% percentile should not be used to set the speed limit. The thinking in much of the US and it seems in some places still in Ireland, is that if most motorists are speeding, then the limit is too low. However, the design of a road or street highly influences the speed at which motorists travel, so if most motorists are speeding, the design is likely not suitable for the context.


  1. It would be great if these signs actually existed I know of a few a good distance away but none within 3 to 4km of my own area and its mainly a 30k area

  2. Do the campaigners using the speed guns incur the cost of the gun themselves or can they acquire one free of charge?

  3. Thanks for this.
    As someone with young kids living on a residential street, the fact that even 1% of the drivers go too fast means the kids are not allowed to play on the street by themselves

  4. In February 2023 I used FOI to ask Fingal CoCo for data from 4 speed reader signs. They told me it would cost 120 euro so I retracted my request.
    The previous September was my first request and they gave me the data for free.
    I might try again with this technique.

    Each reader recorded about 250k records and then stopped saving data. Each record was date/time and speed when vehicle first detected and when last detected (so you can see which vehicles slowed down). I wrote some code to parse it and display some results. Some were depressing. 99km/h was the highest recorded speed – all signs were on 50km/h limit roads.


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