Key:maxspeed:variable

From OpenStreetMap Wiki
Jump to navigation Jump to search
Public-images-osm logo.svg maxspeed:variable
Osm element key.svg
Description
Indication that the speed of a way is not static (e.g. fixed signs) but dynamic (e.g. variable-message sign) Edit or translate this description.
Used on these elements
should not be used on nodesmay be used on waysshould not be used on areasshould not be used on relations
Wikidata
Status: approvedPage for proposal

Tagging

key/value Description
maxspeed:variable=yes Indicates that the speed specified in maxspeed=* tagging represents a maximum speed limit and can be further reduced using dynamic speed indication.
This replaces maxspeed=signals.
maxspeed:variable=<reasons> Same meaning as above, but additionaly specifies one or more ";"-separated reasons for speed adjustment. See next section for possible values.
maxspeed:variable=no Default. Indicates that the speed specified in maxspeed=* tagging is a fixed limit.
Fixed limits can still vary depend on conditions, e.g. time of day.
maxspeed:variable:forward=*
maxspeed:variable:backward=*
Same meaning as above, however, these tags affect forward/backward direction only. If present, overrides maxspeed:variable=*

Values for <reason>

The value can provide additional information, why the speed limit is changed in the variable speed limit section. They should be observable by people frequently using the section with the variable speed limit. If the reason is not known, please use yes.

The values imply a hint about the frequency of a speed limit changes.

maxspeed:variable value Description Example
peak_traffic The speed limit is frequently lowered (from the given maxspeed) on high traffic loads during peak hours on many days of the year. Traffic management systems reduce the speed limit to optimize traffic thoughput by harmonizing the speed of the vehicles, to reduce the inflow traffic into a congested section and also for safety reasons to lower the speed before queues.

The value peak_traffic includes obstruction, adding obstruction to the value (separated by ';') is unnecessary.

Note: This value is not intended for sections with occasional traffic peaks (e.g. start of holidays, an annual concert), even if the variable speed limits is reduced in such situations too. Use obstruction instead.

M25 by Telegraph Hill - geograph.org.uk - 933597.jpg
Speed limit 40 because of dense traffic (rush hour)
weather This value indicates that the speed limit changes with the weather conditions. Most modern traffic management systems have sensors to detect wet road conditions, snow/ice or fog. The information can be used to reduce speed for increased safety.

Note: Only use maxspeed:variable=weather if the speed limit is affected by the weather, not if just warning signs are displayed.

Autobahn im Nebel 2 DSC 0010.jpg

Illustration only, variable speed limit not visible on this picture.

environment The speed limit can be reduced to protect the environment and/or nearby residents (e.g. to reduce emissions, smog or noise).

Note: This value (and maxspeed:variable in general) is not intended for permanent but e.g. time dependent speed reductions like Speedlimit120-timecondition.jpg even if they have been installed for environmental reasons (smog, noise). Use maxspeed:conditional=* instead.

A1 Feinstaub.JPG
Variable speed limit of 100, activated to reduce emissions (indicated by IG-L)
school_zone A lower speed limit is indicated due to children in nearby schools.

Note: This is not a generic tag for school zones. It only applies to school zones where the lower speed limit is changed or indicated externally (for example by switching on flashing lights or changing a digital display) and not just with static signs. For static signs with written conditions like "when children are present", "on school days" or fixed times or days (Mo-Fr, 8-16), please use maxspeed:conditional=* and do not tag it with maxspeed:variable.

Delaware S5-3-DE.svg or Speed limit sign operated from inside of school
obstruction The speed limit is lowered exceptionally in cases like accidents or breakdowns, on occasional traffic peaks (few days of year only, for example start or end of school holidays), road works or other traffic obstructions ahead.

Note: Variable speed limits in tunnels and at tunnel portals outside urban areas are candidates for maxspeed:variable=obstruction.

Gleinalmtunnel.jpg

Here the tunnel has been completely closed due a car break down ("Panne"), the reduced variable speed limit would be 30.

Examples

  • maxspeed:variable=yes, maxspeed=80 – indicates that the maximum allowed speed is 80 kmph, however, this speed limit can be reduced further to accomodate traffic conditions
  • maxspeed:variable=yes, maxspeed=none – indicates that there is no maximum allowed speed (no legal limit!), however, the speed limit can be reduced if necessary. Normally only useful on German Autobahn.