|Destination signs at or before intersections|
|Status: in use|
|Tools for this tag|
This relation allows information about destination signs at crossroads to be entered into OSM. When using a routing software as navigational aid, it is very helpful to be shown the signs to follow. E.g. instead of just saying "Turn left in 200m" a routing software also could say "Follow the sign to Österstad".
Note: The originally intended purpose is rendering on navigators or in turn-by-turn descriptions when following an already made route - in the original intent this is not for aiding the creation of routes.
Should I use a destination_sign relation or destination=* keys?
The destination_sign relation can be used in situations where destinations specified on signs differ, depending upon which direction you are arriving from. This can happen at roundabouts and intersections involving two-way roadways. In these cases, a destination_sign relation provides unambiguous guidance, in the form of multiple destination_sign relations. Even so, destination_sign relations can still be used at intersections where all signs in all directions are identical.
destination_sign relations assume that the intersection node is the turning decision point for a driver. If you wish to indicate destinations before the junction on a per-lane basis, destination_sign relations are not capable of holding this information. For those, destination:lanes=* keys (as explained in Lanes), can be used.
In contrast, destination=* keys are tagged on the road leaving the intersection towards the signposted destination. Multiple destinations can be tagged as semicolon-separated values. At least the first section of a road leaving the intersection needs be tagged for this approach.
This makes destination=* keys and subkeys a popular choice among editors for the typical highways and intersections where indicated destinations are identical from all perspectives; on waterway relations (waterways are by definition are one-way, their direction of flow).
Please note that the destination_sign relation, the keys destination=* and destination:lanes=* are different concepts to support the announcement of signposted destinations, which can be differently evaluated by the navigation software. As they do not conflict, all approaches can co-exist on a particular road.
|type||destination_sign||destination_sign||The type of relation.|
|destination||a name||ÖSTERSTAD||The destination as it says on the sign. Distance not included.|
|distance||a number km or mi||16 km||The distance reported on the sign (Optional)|
|time||hh:mm||3:15||The time reported on the sign/guidepost (Optional and for trekking)|
|colour:back||a colour||blue||The background colour of the sign. (Optional)|
|colour:text||a colour||white||The text colour of the sign. (Optional)|
|colour:arrow||a colour||white||The border/arrow colour of the sign. (Optional)|
|destination:ref||a reference||A 16 East||The reference as indicated on the sign. (Optional) See Destination details.|
For signs pointing to a feature, the tag destination:symbol=* could be used.
For signs with multiple destinations, one destination_sign relation should be created per indicated direction. (When multiple destinations are indicated per direction, these can be listed in the relation's 'destination' field separated by semicolons. If supplementary information must be provided, like distance or time, one destination_sign relation per destination should be created).
Colours should default to some (preferably national standard) presets if omitted. This is handled by the routing/map showing software. Since shades of yellow are probably not interesting, we don't see a need to specify an RGB-colour. Colours could (should?) be chosen from a set list e.g. black, white, red, blue, green, brown, and yellow. See colour=* for possible values.
destination_sign does not support empty role members; a role as specified above must be added to each relation member.
- Original proposal
- destination=* – a different solution for mapping the text and effects of destination signs (but not the signs themselves as positional objects or sign design).
- If you are using JOSM, check the style "Lane and road attributes" from Martin Vonwald. It shows the attributes lanes, turn, destination and Relation:destination_sign.
Notes to makers of routing software
Once again: the originally intended purpose is rendering on navigators (like this - in the next intersection follow the sign "E4 Malmö") or in turn-by-turn descriptions when following an already made route - in the original intent this is not for aiding the creation of routes.
- Check for destination_sign-relations along the route (which is already made and we are about to follow).
- Keep all relations where the route passes the intersection or from member and then the to member of the same relation.
- Remove all relations that have from member(s) but no from member is being passed through by the route.
- If necessary (e.g. on devices with small screens) remove relations (in a smart way) so there are fewer relations shown in each intersection.
- A good routing software would look ahead and see what destinations are shown further down the road and minimize the number of different destinations shown. One of the better ways to reduce signs is to follow signs with the same destination for as long as possible. E.g. if I'm going to Timrå I should follow the sign "E 4 Sundsvall", but I could also follow the sign "Umeå" and then "Örnsköldsvik" and then "Sundsvall" and I would still be following the exact same route. It's just a little more convenient to follow the Sundsvall-sign from the beginning.
- Show to the user a sign (possibly with specified colours) with the name from the destination-tag.
This schema is supported by the following software:
- None known to date
- There is a map showing destination signs and rendering them based on this tagging scheme: