UK roads speed limits data

Hello - from today, there are punitive laws to punish drivers who exceed the speed limit. My project is to add a GPS module and a display to a Raspberry Pi, and to position it in my car so that it always shows me the maximum speed limit prominently, and even makes a noise when I drive too fast. For that, I need to be able to have available the speed limit as I move along, and my idea is to have a summary of GPS location and maximum speed limit data in a database on the Pi. I’m not intending to provide any kind of map, just an easily read display of two digits of the current speed limit wherever I am in the UK. That’s why Google has led me to OSM, which from what I see contains this kind of data. My life to date has been completely innocent of any kind of contact with mapping software. :slight_smile:

Is there an OSM expert out there who can tell me what would be the best place to download and extract the information I need?

Thanks for any advice.


I hadn’t heard of an increase in speeding penalties, but then I don’t own a car. It sounds overdue to me, given that I estimate speeds of up to 40 mph on the local 20 mph limit road.

However, before you spend too much time on this, please look at

You will find that the speed limit coverage is very patchy. Not even all major roads are covered and the coverage of 20 mph limits will be particularly patchy.

I don’t know if any of the paid for mapping databases have better sources for speed limits, but crowd sourcing is not something you should rely on to protect your licence. I would expect even commercial providers to disclaim responsibility for relying on them rather than using your eyes.

hadw - Depending on how much the driver exceeds the speed limit, from today the beak can fine them up to 1.5 times their weekly income. There’s a 40mph limit outside my house which most drivers seem to regard as optional, or a challenge. Sadly, flogging and transportation are no longer options.

Yes, thanks for the link, I see what you mean, the coverage is so patchy as to be useless. That’s disappointing, but now I know. Many thanks for your help.


Also take a look at that map:

I’m new here so correct me if I do something wrong.

I understand that the UK maxspeed is a bit patchy but I think that it can be improved.

Using the ITO map I see that Hull has essentially complete speed limit coverage on all the city’s roads.

North Lincolnshire its’ next door neighbour, excluding Barton and the motorway, has virtually none.

The North Lincolnshire Councill is responsible for setting the speed limits and got all the maxspeed data which it puts on its’ own map.

It uses OSM maps on its’ webpage but doesn’t seem keen on letting OSM use their maxspeed data.

Question. Is there a way of automatically extracting road data from a councils’ data, including maxspeeds in a form which can be used to update the OSM maps? IE a batch job?

I bet Hull didn’t update all there roads individually by hand!


@Crumbleey: I would expect most roads in Hull might have been surveyed by an OSM contributor. Nothing to do with the council.

Unfortunately we have never had any very active contributors in Lincolnshire as a whole and in North Lincs in particular. Grimsby was probably the last town of any size in the country to have no pubs mapped on OSM. This is the main reason we dont have speedlimit data too.

Unless we have explicit permission from a council to use their data (and it must not be tainted with Ordnance Survey data) then we cannot use it in OSM.

It is entirely possible to make reasonable assumptions: all residential roads are 30 mph or 20 mph if one knows a council has rolled out a 20 mph programme. Other roads in a built-up area are 30 mph, etc. Visual sources uch as Geograph, Mapillary & OpenStreetCam can also play a role: but are also subject to the patchy contributor distribution.