The use of Ordnance Survey roads data in satellite navigation systems

Ordnance Survey produces digital road data that supports a variety of applications across the public and private sectors from routing and navigation to asset management.

Information on the road network is gathered by surveyors working from field offices across the country and complemented by an intensive programme of aerial photography. We also incorporate local authority information on road names and specifications. We aim to capture all significant changes to the road network within six months of them occurring.

This data is then supplied to private mapping companies who use it for input to the manufacturers of in-car, personal navigation systems. Ordnance Survey does not recommend particular routes or say any particular route is faster or slower than another.

The companies who receive our data add more information to it, which makes the routing applications possible. It is their role to attribute routes with a weighting of importance. This depicts the order in which the navigation software will route the user. It includes additional information such as the number of lanes on a motorway, feedback from users, feedback from local traffic surveys and other observations. 

There is a variety of classification weightings that help the satellite-navigation manufacturers to ultimately differentiate their products from each other and prioritise routes. To arrive at a recommended journey they will also take into account user instructions such as whether the driver wants the shortest or fastest route, a journey only on A roads, a journey only on motorways, and so on. Much will depend on the choice of product.

Before an amendment in our underlying data can appear in a publicly available satellite navigation system, it will first have to be fed into a route mapping company’s technological processes and refreshed in the manufacturer’s product, so it can take some time before a change in the physical landscape captured by Ordnance Survey features in a system.

If a sat nav user wants to be as up to date as possible, they will have to purchase the latest and most up-to-date dataset and keep this maintained. They should be aware that not all sat navs are the same and the data contained within different products varies considerably.

If you are a haulier you have greater need for information on road weight, width and height restrictions than an occasional weekend leisure user. This road restriction information is something Ordnance Survey has offered customers of its road network data since October 2006.

Ordnance Survey believes the best way to avoid unwanted heavy trucks rumbling through small villages is to see separate passenger car and commercial vehicle sat navs. We are pleased that the Freight Transport Association has called for the industry to adopt an appropriate satnav to deal with this issue. Similarly, the DfT Best Practice Guide for sat nav advocates the benefits of specialist HGV attributes.