Speed Limit Map
TfL have published a “London Digital Speed Limit Map“, showing speed limits for cars on a map of London’s public roads, for the last few years. It is updated annually, and TfL have just released a 2017 version. The map is published alongside data supplied to digital mapping data providers, so that they can program in the correct speeds for satnavs in cars.
The updates over the last few years reveal the gradual switch, in inner-city London boroughs, from 30mph (blue) to 20mph (green) limits for residential roads. In 2017, this has resulted in a glaring hole in west-central London, where Westminster, Kensington & Chelsea and Wandsworth boroughs have resolutely stuck to allowing motorised traffic to travel at up to 30mph in residential areas, with a few small area exceptions (e.g. Queen’s Park in Westminster borough).
This is not a particularly pretty map to look at, being essentially the output from a GIS (geographic information system) rather than a cartographically produced work designed for regular viewing. The 20/30 split is clear but the colours used to distinguish 30/40, and 50/60/National are hard to see – not that many roads in London have speed limits about 30mph anyway. The trends described above, however, are clear. Zooming in a long way helps, revealing your local familiar street network. Nonetheless, it deserves inclusion on Mapping London as it is an important snapshot of how different parts of London are evolving from car-centric design to a more inclusive street scene.
Spot the Westminster borough boundary:
As well as these official maps, OpenStreetMap contributors have been diligently adding speed tags to the roads of London (and indeed the rest of the world) and a special ITO World render shows them on a similar, but prettier, map:
The top two maps are © Crown copyright and database right Ordnance Survey and © Collins Bartholomew. The last map is © OpenStreetMap contributors with the map tiles © ITO World and CC-By OpenStreetMap contributors.