Differences between OSM and Sustrans mapping of National Cycle Network

There are thousands of differences between OSM and Sustrans mapping of the National Cycle Network (NCN) in the United Kingdom. Sustrans wants to work with the OSM community to resolve these differences, so the mapping of the NCN is more accurate. Sustrans has created an interactive map showing these differences.

Background

Sustrans was alerted to this issue by Ian Dent in 2023. He posted an outline of the issue on Talk-GB, which includes a link to his analytical website Sustrans NCN inconsistences.

Sustrans took Ian's method to create their own comparison between the NCN alignment on OSM and their own mapping, which was published in April 2025.

Simon Pratt, who worked with Sustrans for 28 years, has taken on the voluntary task of resolving these differences.

Sustrans differences map

Sustrans has created an interactive map showing the differences.

The map provides direct links to OSM for editing where there is a an obvious error in OSM, to enable that to be fixed. There is a feedback mechanism if the error appears to be with Sustrans mapping, to give feedback to Sustrans.

This dataset is automatically generated from a GIS process that identifies route alignment differences between the National Cycle Network as drawn in OpenStreetMap (OSM) and the National Cycle Network as drawn by Sustrans. This data can be used to spot-check and rectify alignment differences in OSM. The dataset is updated every Sunday morning.

Extraction query

OSM data is derived from Overpass Turbo using the following query; if you can think of a better query to extract Sustrans data from OSM, please let us know:

[out:json];
area[name="United Kingdom"];
(
	rel(area)[network~"rcn"][state!="proposed"][route!="mtb"][!operator]->.a;
	rel(area)[network~"rcn"][state!="proposed"][route!="mtb"][operator~"sustrans",i]->.b;
	nwr(area)[network~"ncn"][state!="proposed"][route!="mtb"][!operator]->.c;
	nwr(area)[network~"ncn"][state!="proposed"][route!="mtb"][operator~"sustrans",i]->.d;
	nwr(area)[network="ncn"][state!="proposed"][route!="mtb"][cycle_network="UK:National CycleNetwork"]->.e;
);
(._;>>;);
out;

Processing

Sustrans and OSM NCN are buffered by 100 metres and three alignment differences are captured where the areas don't overlap:

Category	Description	Suggested Action
OpenStreetMap aligns with Sustrans 'reclassified' route	Sustrans reclassified this route in 2020 and no longer considers it part of the National Cycle Network.	Sustrans is working with volunteers to resign it. Use the link to correct the feature in OpenStreetMap
OpenStreetMap does not align with Sustrans NCN route	This feature is drawn in OpenStreetMap data but not in Sustrans data.	If you think this is an error, use the link to correct OpenStreetMap. Alternatively, use the feedback button to notify the Sustrans Network Development team if you think it's missing from Sustrans data.
Sustrans NCN does not align with OpenStreetMap	This feature is drawn in Sustrans data but not in OpenStreetMap.	Use the feedback button to notify the Sustrans Network Development team if you think this is an error. Alternatively, use the link to digitise the feature in OpenStreetMap.

Removal and Reclassification

In June 2020, almost 4,000 miles were removed from the Sustrans NCN mapping with 80% reclassified as regional or local routes.

Unfortunately, it has taken much longer than planned to change the signs on the ground and there are still some differences between the Sustrans NCN mapping and the signs with a red number patch designating a NCN route.

Regional routes

When the NCN was launched in 1995, three types of route were envisaged:

• National routes (red number patch)
• Regional routes (blue number patch)
• Local routes (determined locally)

Sustrans stopped mapping local routes several years ago, because they did not have the resource to maintain such a large dataset. As part of the Removal and Reclassification process, Sustrans decided that Regional Routes should be treated in one of three ways:

1. Removal of the route from Sustrans mapping
2. Reclassification as a named and promoted route
3. Designation and re-signing as a National Route with a red number patch

This process has also taken much longer than expected, but it remains the intention to eventually remove all Regional Routes from Sustrans NCN mapping. For this reason, Regional Routes are excluded from the Sustrans Differences map.