Proposal:Conditions for access tags

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Conditions for access tags
Proposal status: Abandoned (inactive)
Proposed by: Tordanik
Tagging: maxspeed:<condition>, access:<condition>, ...=*
Applies to: *
Definition: an access tag only applies if the condition is fulfilled
Statistics:

Draft started: 2009-01-24
RFC start: 2009-01-28

This proposal contains some extensions to existing access tagging. They all use an existing key (such as maxspeed and access), but append a condition, separated by a colon (":").

Possible conditions

German add-on sign "when wet"
German add-on sign "hgv"

This section lists all proposed key extensions.

By vehicle category

Examples include:

Any vehicle category (as listed on Key:access) is a possible condition. The access tag is then only valid for vehicles from that category.

By road condition

  • :wet - access tag is only valid when the road is wet

By lighting condition

  • :night - access tag is only valid at night (in darkness)

By direction

  • :forward - access tag is only valid in way direction
  • :backward - access tag is only valid against way direction

(Note that this 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.)

Evaluating "conflicting" tags

  1. More specific information overrides more general information (for a wet road, maxspeed:wet overrides maxspeed).
  2. If there are conflicting tags without a "specificness" hierarchy, the most restrictive rule (e.g. lowest maxspeed) is to be chosen.

Examples

Tagging Interpretation
maxspeed=100

maxspeed:hgv=60

Maxspeed is 100 km/h for most vehicles, but 60 km/h for hgv traffic:
maxspeed=120

maxspeed:wet=80

Maxspeed is 120 km/h under normal conditions, but 80 km/h when the road is wet:
motor_vehicle=no

psv=yes

oneway=yes

bicycle=no

hour_on:bicycle=10:00:00

hour_off:bicycle=18:00:00

Bicycles are permitted to use this street outside 10AM-6PM, but not during most of the day. Other modes of transport have different rules applicable to them. Based on Queen Street in Oxford UK.

(Note that the follow-up proposal "Extended conditions for access tags" removes the need for hour_on/off, replacing it with the more flexible opening_hours value syntax.)

Notes

existing tagging

Some existing tags could be expressed with conditions, for example

  • oneway=yes is equivalent to access:backward=no
  • cycleway=opposite is equivalent to oneway:bicycle=no
  • ...

This proposal does not deprecate those widely used tags.

way direction dependency

The following tags affected by this proposal depend on way direction:

  • tags with ":forward" or ":backward" as part of the key
  • tags starting with direction-dependent main keys (e.g. "oneway:...")

Editors should include those tags in their way reversal safety checks.

Debate

Comments

Please use the talk page.

Opinion Poll

Please indicate whether you like the proposal (using {{Poll|yes}} or {{Poll|no}}). You can add a short comment, but please use the talk page where appropriate.

My understanding is that this restriction could be represented as a combination of hour_on:hgv=T1, hour_off:hgv=T2, and maxspeed:hgv=S with this system. The meaning of hour_on/hour_off is that the global restriction applies between the started times. By analogy, the qualified version means that the qualified restriction applies between the started times. Easy; see the example for bicycles. --achadwick 20:20, 21 February 2009 (UTC)
  • I like this proposal. --Seehundeführer 08:14, 07 June 2009 (UTC)
  • I like this proposal. --Longbow4u 09:47, 7 June 2009 (UTC) On e.g. maxspeed=forward:60 there is the problem if a later user changes the direction of ways for other reasons, e.g. rendering of the name tag. Then the maxspeed tag would be wrong in both directions. Perhaps for this case there should be a warning implemented in the OSM editors: "Warning! There is a direction depending tag (link to "direction depending tag") in the ways you are going to change. Are you sure you want to proceed? YES NO"
JOSM already does that, but only if the key begins with 'forward:' or 'backward:' Alv 10:33, 7 June 2009

(UTC)

--Phobie 11:33, 16 June 2009 (UTC)

For those who want opening_hours syntax instead (and I'm one!): would you be happy with the term access_hours, and to allow qualifications like access_hours:psv=*? Calling the access times for a road "opening hours" sounds wrong to me as a native English speaker, "access times" has a better ring to it, and "access hours" seems like a good compromise that echoes the opening_hours=* name. --achadwick 20:18, 25 April 2011 (BST)

Don't forget that access_hours wouldn't solve things like time-based maxspeeds. And any solution that works for time-based maxspeeds will also work for access, rendering the special solution for access redundant. --Tordanik 09:52, 6 May 2011 (BST)

See also