User:Bielawski/Sandbox/Sign proposal

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General-purpose signs
Status: Draft (under way)
Proposed by: Bielawski
Tagging: *=*
Applies to: Relation
Definition: *
Rendered as: n/a
Drafted on: 2009-06-02
RFC start: FIXME
Vote start: *
Vote end: *


This proposal is to describe the exact signs used to direct traffic so that routing software can give more accurate instructions and show previews of signs. The idea of describing signs is ripped off from Cohan's proposal


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 "Make a slight right at exit 1" a routing software also could say "Follow the sign to route 342 east toward Pointe-Fortune (exit 1)" and show an approximation of how the sign will look.


The basic thing that sets this proposal apart from the previous one by User:Cohan is that it supports more information on the sign than a destination. Each type of sign (by type I mean something specific, e. g. a sign in Texas denoting an exit to a US highway that shows it as the route to two towns and an airport) has a memberless template relation that contains both a textual description of the sign type and a SVG representation, both including fields that will be filled in by the relations representing the actual signs.

The sign relations are similar to the ones proposed previously, except that they have as a member a template relation as described above and have tags corresponding to the fields in the template.

Tagging: template relation


Key Value Example Comment
type sign_template sign_template
svg URL to an SVG image (preferably hosted by OSM) representing an example of the sign. In the sign image, fields are marked using $(FIELD_NAME).
text:en Textual description of the sign, including fields Road $(ref:road) – $(name:left) to $(city:left) and $(name:right) to $(city:right) (Exit $(ref:exit)) One tag per language

Tagging: sign relation


The tags for this relation correspond to the fields defined in the template relation. For example:

Key Value
ref:exit 336
ref:road 1
name:left  Mississauga Road
Et cetera...


Way or Node Role Recurrence? Comment
Node sign exactly one The point where the sign is. This could be an intersection or a point before it. In the example this is [Node B].
NodeWay to exactly one [Node C/Way W] A (the first) way/node on the way after the junction
NodeWay from optional [Node A/Way Q] A (the last) node/way before coming to the junction.

Unnecessary when destination signs are the same from both directions. (D-B-C = A-B-C)

Node via optional [Node B] The node where the roads cross
Relation template exactly one The template that the sign uses.


Lets say I'm approaching the crossing in the photo on the top of this page and the routing software says that I should turn left. It would be an additional aid to know that I want to follow the sign to Österstad. This aid becomes increasingly helpful when following a larger road with many exits or crossing ways.

Destination sign relation.png

The relations for the signs in the picture: (Assuming that the signs are not visible from the Åsmestad road.)

<relation id="??">
  <tag k="type" v="destinationSign" />
  <tag k="destination" v="ÖSTERSTAD" />
  <tag k="colour:back" v="blue" />
  <tag k="colour:arrow" v="white" />
  <tag k="colour:text" v="white" />
  <member type="node" ref="B" role="sign" />
  <member type="way" ref="W" role="to" />
  <member type="way" ref="Q" role="from" />

<relation id="??">
  <tag k="type" v="destinationSign" />
  <tag k="destination" v="Åsmestad" />
  <tag k="colour:back" v="yellow" />
  <tag k="colour:arrow" v="red" />
  <tag k="colour:text" v="black" />
  <member type="node" ref="B" role="sign" />
  <member type="node" ref="D" role="to" />
  <member type="way" ref="Q" role="from" />

Questions to be ironed out

  • How to do when more than one sign is pointing in the same direction. One relation for each sign (destination) or can this be managed within one relation? Only entering one (the topmost) sign?
  • Should caps be used if used on sign? In Sweden, as the example photo shows, destinations along major roads are written in caps while destinations along minor roads are not.
  • Sometimes an icon is used as destination, especially for airports. How to handle this? Special strings like {AP} and let the routing software show a proper icon instead?
  • Signs specifying a destination and a road number, e.g. E4 Umeå. The road number might have different colours than the rest of the sign.
  • Signs not specifying a destination, only a road number.

See also


Discussion on the Talk page