The Thames Path is a UK National Trail following the River Thames from its source near Kemble (Gloucester) to the Thames Barrier in London. See the external links for general information about the path - this wiki page exists to document the conventions for mapping the trail on OSM.
Relation 20469 is currently being used for the route as a whole. It could be argued that using a single, simple relation is not the best way to represent the path, as there are several alternative choices of route along the way:
- The main path crosses the Thames using the Shepperton to Weybridge Ferry. An alternative route exists through Shepperton (crossing the river further downstream, at Walton Bridge), for use when the ferry is not running.
- The path has north bank and south bank alternatives through central London (between Teddington Lock and Greenwich). The two alternative routes have equal status as part of the official National Trail (though the length for the trail that is normally quoted, 184 miles, seems to be based on the south bank route).
- The trail head at the London end of the National Trail is at the Thames Barrier. There is an extension to the path (the Thames Path Southeast Extension), which continues the route a further 10 miles (16km) downstream to Crayford Marshes. This is not an official part of the National Trail, and uses a different set of waymarks to the National Trail. It is considered part of the Thames Path by some (the Rambler's Association list it as part of the Path, for example).
Currently, relation 20469 follows the main route over the Shepperton/Weybridge ferry and predominantly follows the south bank route downstream of Teddington, but the same relation also contains a few isolated segments of the Shepperton alternative route and the north bank route through London. Substantial parts of the South East Extension are also present in relation 20469 at the moment.
A separate relation should probably be created for the South East Extension.
A separate relation should probably be created for the Shepperton alternative route.
A separate relation could be created for the central London north bank route, using relation 20469 to represent the 184 mile linear route from the source to Thames Barrier. Alternatively the official trail could be represented by four separate linear route relations (source to Teddington, central London north bank alternative, central London south bank alternative, Greenwich to Thames Barrier) and a super-relation used to group them together.
The Thames Path now appears complete. All routes west of Teddington have been mapped on both banks. With the increasing number of London walks now being added to OSM there is a pressing need for the means of displaying and using the data - especially by non-OSM users. There should probably be a Wiki page devoted to a development strategy for the presentation and printing of data on both long-distance and local walks.