Proposed features/Modifiers for access tags
|This proposal has been obsoleted by Proposed features/Conditions for access tags and Proposed features/Extended conditions for access tags.|
|A number of alternate solutions have been proposed. For a full list see Proposed_features/Advanced_access_tags. Update Oct-2012: The Conditional Restrictions proposal was approved by a majority vote.|
|Modifiers for access tags|
|Tagging:||[[Key:maxspeed<:modifiers>, access<:modifiers>, ...|maxspeed<:modifiers>, access<:modifiers>, ...]]=[[Tag:maxspeed<:modifiers>, access<:modifiers>, ...=*|*]]|
|Definition:||an access tag with access modifiers only applies if all conditions given as modifiers are fulfilled|
Many common traffic regulations cannot be tagged properly because of the lack of a comprehensive and consistent way of limiting the restrictions to certain vehicle types, road conditions or road users. This proposal defines a set of access tag modifiers together with a way of adding them to the base tag.
Overview and initial examples
The modifiers are separated from the base key with a colon (':'). If, for example, only destination traffic is allowed to use a street with the hgv vehicle category, this can be tagged as
- access:hgv = destination // note: bad example (could be expressed as hgv=destination), looking for better one ;-)
If multiple values with different modifiers are present, the most specific one that matches the current situation is used. So if the maxspeed differs depending on whether a road is wet or dry, this can be tagged as
- maxspeed = 120
- maxspeed:wet = 80
Modifiers are separated from each other using '&'. If there was an even lower maxspeed for hgv on the wet road mentioned above, this could be expressed by adding
- maxspeed:hgv&wet = 60
This section lists all proposed modifiers.
Any vehicle category (as listed on Key:access) is a possible modifier. The access tag is then only valid for vehicles from that category.
The user categories
can be used as modifiers. The access tag is then only valid for users from that category.
describes that an access tag is only valid when the road is wet.
- forward - access tag is only valid in way direction
- backward - access tag is only valid in way direction
(Note that is different from lane-specific information: There are ways with direction-dependent restrictions that do not have multiple lanes. There also can be multiple lanes for each direction.)
Restrictions can be limited to vehicles with certain dimensions using
- weight <comparator> <value>
- height <comparator> <value>
- width <comparator> <value>
- length <comparator> <value>
- axleload <comparator> <value>
- draught <comparator> <value>
where <comparator> is one of '>' (more than) and '<' (less than). <value> is given as with maxweight, maxheight etc.
describes that vehicles (and animals) with a weight of more than 3.5 t must not move faster than 90 km/h.
- More specific information overwrites more general information (for a wet road, maxspeed:wet overwrites maxspeed).
- If there are conflicting tags without a "specificness" hierarchy, the most restrictive rule (e.g. lowest maxspeed) is to be chosen.
Notes on existing tagging
Some existing tags could be expressed with modifiers, for example
- maxweight=3.5 is equivalent to access:weight>3.5=no
- oneway=yes is equivalent to access:backward=no
- cycleway=opposite is equivalent to oneway:bicycle=no (or access:backward&bicycle=yes)
This proposal does not aim to abolish those existing tags, as the existing tags are widespread, shorter and more easy to understand.
- time of day, dates (similar to weight etc., but requires time format)