allmapdata Makes Free UK Daily Traffic Flow Data More Usable for Analysis

Free data from the UK Government on numbers of vehicles on the road has proved an invaluable resource for analysis and policy development by research bodies and “think tanks”, but in its raw form the data is not ideal for the kind of precise and accurate spatially-related analysis that these organisations aim for.

By linking this data more precisely to the actual roads in question, Mapmechanics has now made it much easier for one organisation to harness this data in order to perform more accurate and meaningful analysis relating to roads and traffic.

As a result, the data can be used readily for practical projects such as analysing vehicle breakdowns and accidents in relation to traffic flows, or evaluating the data from air quality monitoring sites in relation to traffic density and vehicle types on nearby roads.

It was a fiddly job for any organisation to take on, but Mapmechanics willingly took up the challenge, and has provided the solution at a very decent price.

Mapmechanics is one of Britain’s leading specialists in digital map data and software for displaying and analysing maps. Among its key services, it provides a bespoke development capability to clients needing special map-related software functionality.

The UK Government’s free “Annual average daily flow” product provides street-level data on traffic flows for an average day of the year over every link on the motorway and A-road system in Great Britain.

before-daily-traffic-data

Before: Raw data depicting straight lines between junctions

However, the data only shows traffic measurements as precise point data, when it is more appropriate to think of it as a line data (usually the links between main junctions). This means that it is not possible to plot the data accurately on a map and perform spatially-related analysis on it. The basic shapefile (vector map file) provided with the data means that information will often appear some distance from the actual road – in some cases even on another nearby road.

Consultancies and research organisations have adopted a range of sometimes complex strategies in order to link the traffic counts more precisely to the roads they refer to.

After: Processed data depicting accurate lines following road segments

After: Processed data depicting accurate lines following road segments

Mapmechanics was asked by one such research organisation if it could come up with a simple but robust solution that would make it easy and practical to use the data from day to day. In response, the company has developed a road network diagram based on the data, which can be displayed in Ordnance Survey’s Meridian 2 vector digital road map (part of OS’s free OpenData product range).

In the resultant map, the road links used in the Traffic counts dataset follow the routes of real roads closely. According to a spokesperson for the research organisation:

This improves visualisation enormously, and allows proper analysis. Previously we simply couldn’t get at the data in this way. It has been a really good buy for us.

As an example of the benefits, he says: “Lately, we’ve been analysing the extent of electric vehicle charging point coverage on the road network. Previously, we could only do this by length of road; now we can do it by type of vehicle or miles driven.”

He says the new product will also help in the development of simple display of data that is otherwise very difficult for the layperson to engage with – for instance, showing how many people use the Dartford Crossing in a single day.

So useful has the organisation found the Mapmechanics solution that it is now considering applying it in a more granular version of the DfT data, which presents traffic counts for every 15 minutes of the day.