|Used on these elements|
|Tools for this tag|
The key 'route_ref' is used on bus stops to list all bus lines that serve this stop. If a stop is served by several bus lines, all services are listed in the tag, separated by semicolon, e.g. route_ref=12;15;X97. The tag is added to the object tagged as highway=bus_stop or public_transport=platform. Currently (2018-03) about 6.5% of all platforms are tagged with their respective routes using this key.
It enumerates all the lines which serve that bus stop. It's data which can easily be gathered/checked during survey or which can be calculated when timetable data is present under a suitable license.
Combination with relations
Please note that there is a certain overlap with bus routes mapped as relations (see Relation:public_transport). It is not necessary to use both schemes for the same bus stop. route_ref=* can easily be added to individual bus stops without knowing the whole route a service takes. It can serve as a basis to add the full route relation later on. If the full route is known, using a relation should be preferred, as it provides more information and can be shown as a route on dedicated maps or can be used in routing engines.
It was originally used by NaPTAN/Tag_mappings import, but is now used all over the world. In Belgium, it is used on the bus and tram stops of MIVB/STIB.
Situation in Belgium
It became necessary to use a name spaced approach to enable using the same node for stops of different operators/networks. In the mean time the information for the Belgian operators