|Records the source for a speed limit, either a sign, a context (default limit) or a speedlimit zone|
|Used on these elements|
|Documented values: 1|
|Status: in use|
|Tools for this tag|
The source:maxspeed=* tag records the source of a road's maximum Speed limit as provided in the maxspeed=* tag to assist with Verifiability and maintenance. This may be a sign giving a numeric maximum speed, or a 'zone' from which the appropriate numeric speed limit can be determined by knowledge of local traffic laws.
How to tag
- See also: Speed limits
- sign (where the speed limit is defined by a numeric sign.)
- markings (where the speed limit is defined by painted road markings.)
- <country_code>:<context> (where the speed limit is defined by a particular context, for example urban/rural/motorway/etc., and no maxspeed is signposted)
Do not use <country_code>:<context> where there are signs that are prescribing the same maxspeed as the default.
An urban road in Italy would be tagged:
Where the speed limit is indicated by special speed limits signposted at the zone boundaries they can be tagged as follows:
- maxspeed=30 and zone:maxspeed=DE:30 - 32.952 uses 2017-03-30
- maxspeed=30 and source:maxspeed=DE:zone30 - 32.018 uses 2017-03-30
- maxspeed=30 and source:maxspeed=DE:zone:30 - 21.832 uses 2017-03-30
other (less recommended) variations
- maxspeed=30 and source:maxspeed=DE:zone - Proposed by a discussion on a mailing list citation needed (used 4k times in May 2014), usage stagnating according to taginfo history (5779 as of 3/2017)
- maxspeed=30 and source:maxspeed=zone - Proposed in the discussion of this page (analogously to other not country and speed-specific values like sign and markings) (usage stagnating, 1,8k as of 3/2017)
In some areas, default maxspeeds are not uniform in the whole country, in these cases simply use more refined codes referring to the area.
Commonly used values
|source:maxspeed value||maxspeed value|
|FR:motorway||130 /110 (raining)|
Note on British Usage
Some mappers use source:maxspeed=* to tag the source of the information as for other tags of the form source:*. In Great Britain, prolonged discussion of this point on talk-gb resulted in agreement to use source:maxspeed for the data source (survey, Open Data, etc) and maxspeed:type=* for the information described on this page. This usage is more consistent with the general pattern of tagging. It also resolved a conflict about how unsigned national speed limits should be tagged.