Relation:restriction

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One example for restriction
Description
Used for a set of tags and members to represent a turn restriction.
Group
Restriction
Members help
  • Way - from
  • Way - to
  • Way Node - via
  • Node - location_hint
Status
Undefined Status: Undefined
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This is the definition for a set of tags and members making a Relation to represent a turn restriction at a junction or other restrictions (you don't have to be turning - you may not be allowed to go straight on - e.g. a bus gate is a kind of junction where the restriction is no passage from one side to the other - except for buses of course).

There may be several turn restrictions at a junction, represented by separate relations.

There is no need to model no turning into the wrong way of a one way street - we take this for granted.

Turn restrictions do not apply to pedestrian unless the type or key is restriction:foot.

Tags

Key Value Explanation
type restriction / restriction:hgv / restriction:caravan / restriction:motorcar / restriction:bus / restriction:agricultural / restriction:bicycle / restriction:hazmat Restriction refers to all vehicles or only to appropriate type of vehicles.
(you can use type=restriction:<type> + restriction= or type=restriction + restriction:<type>=[1])
restriction no_right_turn / no_left_turn / no_u_turn / no_straight_on / only_right_turn / only_left_turn / only_straight_on / no_entry / no_exit

If the first word is "no_", then no routing is possible from the "from" to the "to" member, and if it is "only_", then you know that the only routing originating from the "from" member leads to the "to" member.


restriction:hgv, restriction:caravan, restriction:motorcar, restriction:bus, restriction:agricultural, restriction:motorcycle, restriction:bicycle, restriction:hazmat no_right_turn / no_left_turn / no_u_turn / no_straight_on / only_right_turn / only_left_turn / only_straight_on / no_entry / no_exit

Restriction refers only to appropriate type of vehicle.
(you can use type=restriction:<type> + restriction= or type=restriction + restriction:<type>=[1])

except psv / bicycle / hgv / motorcar The restriction does not apply to these vehicle types (more than one: except=bicycle;psv)
day_on day of week for example, no right turn in the morning peak on weekdays might be day_on=Monday;day_off=Friday;hour_on=07:30;hour_off=09:30
day_off day of week
hour_on time of day
hour_off time of day


Members

Way or node Role Recurrence Discussion
Way from 1

1 or more

A way from which restriction starts (e.g., no right turn from here).[2] A no_entry restriction can have more than 1 from member, all others have exactly 1 from.
Way to 1

1 or more

The other end of the restriction.[2] A no_exit restriction can have more than 1 to member, all others have exactly 1 to.
Node
Way
via Node: One (1) node

Way: One (1) or more ways

The via member(s) connect the beginning and end ways representing the allowed or restricted maneuver. As shown to the left, a turn restriction can either have (i) one node or (ii) one or more ways with a via role.

The nodes or way between the end points across which you would travel if the turn weren't restricted - may just be the simple intersection of the two ways, or consider a dual carriageway where you can't turn across it, where via would be the nodes on each carriageway and/or the little way connecting the two carriageways[3].

Node location_hint 0 or 1 A hint to a renderer as to where might be a good place to position a symbol indicating the restriction. E.g., in a N/S/E/W cross roads where you can't turn from S to E, you might put a node just SE of the junction and the renderer might place a no right turn sign there.
Intersection TurnRestriction ViaNode.PNG
Turn Restriction with a node as the via member.
Intersection TurnRestriction ViaWays.PNG
Turn Restriction with multiple ways as a via member.

Road signs

The sign number in the US MUTCD is given in parentheses. There are slight differences of these roadsigns from country to country. Images of turn-signs all around the world can be found on Wikimedia Commons

Note: The symbols for restrictions displayed in editors are not authoritative; tagging must not rely on them. E.g., a no_right_turn in JOSM displays symbol 4a (straight ahead and left) even if there is no left turn. The relation members and restriction value are the important part.

Road sign Restriction Remark
1 a Only straight on or right turn.png restriction=no_left_turn Germany, Italy, Japan, The Netherlands, Russia, Ukraine, Romania (restricts U-turn as well)
1 b No left turn b.png restriction=no_left_turn Australia, Brazil, France, Ireland, Poland, Russia, Spain, Switzerland, UK, Ukraine, US (R3-2; R3-18 combined with no U-turn)
2 a Only straight on or left turn.png restriction=no_right_turn Germany, Italy, Japan, The Netherlands, Russia, Ukraine, Romania
2 b No right turn b.png restriction=no_right_turn Australia, Brazil, France, Ireland, Spain, Poland, Russia, Switzerland, UK, Ukraine, US (R3-1)
3 a Only left turn or right turn.png restriction=no_straight_on Germany, Israel, Japan, The Netherlands[4], Poland, Russia, Switzerland, Ukraine
3 b No straight on b.png restriction=no_straight_on Brazil, Ireland, US (UK and France never use such signs; you would usually be facing a no entry sign in such a situation, or if it's two-way ahead you might see adjacent left-turn-only and right-turn-only signs)
4 a No u turn a.png restriction=no_u_turn Brazil, France, Germany, Israel, Japan, The Netherlands, Poland, Spain, Switzerland, Russia, Ukraine, US (R3-4)
4 b No u turn b.png restriction=no_u_turn Australia, UK
5 a Only right turn a.png restriction=only_right_turn Typically on the approach to a junction.

In the US, a white rectangular sign is used for this situation and the case where one lane on a multi-lane road must turn (R3-5R).

Ukraine (just before a junction).

5 b Only right turn b.png restriction=only_right_turn Typically at the junction.

In the US, a white rectangular sign is used for this situation and the case where one lane on a multi-lane road must turn (R3-5R).

6 a Only left turn a.png restriction=only_left_turn[5] Typically on the approach to a junction.

In the US, a white rectangular sign is used for this situation and the case where one lane on a multi-lane road must turn (R3-5L).

Ukraine (just before a junction).

6 b Only left turn b.png restriction=only_left_turn Typically at the junction.

In the US, a white rectangular sign is used for this situation and the case where one lane on a multi-lane road must turn (R3-5L).

7 Only straight on a.png restriction=only_straight_on Used in Russia, in Ukraine and in the UK; usually seen just before a junction or on the approach to a junction.

In the US you'll see the text "NO TURNS" in a white square (R3-3; R3-5a is usually used only in the case where one lane on a multi-lane road must turn).

8 3.1 Russian road sign.svg restriction=no_entry Used for not one-way roads, where entering across some point (member node with role via) is prohibited. Relation can have several from members[2] and one to member.

In Ukraine is used for opposite-direction one-way road entries, and for roads that even residents are not allowed to drive.

9 3.1 Russian road sign.svg restriction=no_exit Used for not one-way roads, where exiting across some point (member node with role via) is prohibited. Relation can have one from member and several to members.[2]

Obviously, the above table can't be complete; e.g., swedish road signs use a yellow background instead of the white one. However, with the above signs it should be easy to find the corresponding restriction=xy value for most countries.

In Brazil, all signs in this category, whether no_turn or only_turn is a red circular sign with an arrow pointing in the direction. only_turn signs does not have the diagonal bar, while no_turn signs have (similar to 1-3b, but also for 5-7).

Examples

Map Tag and Members Descriptions
Only right restriction.png type=restriction

restriction=only_right_turn

  • way A has role 'from'
  • way B has role 'to'
  • node n has role 'via'
At n from A only turning right to B is allowed. So turning to left is forbidden.
No left restriction.png type=restriction

restriction=no_left_turn

  • way A has role 'from'
  • way B has role 'to'
  • node n has role 'via'
Turning left form A to B is not allowed at n. But going straight and right is not forbidden. Each of the other 3 restrictions at this crossing have to be defined separate.
Via way restriction.png type=restriction

restriction=no_right_turn

  • way A has role 'from'
  • way B has role 'via'
  • way C has role 'to'
Users coming from way A cannot exit through way C.

Editors

Errors

References

  1. 1.0 1.1 The restriction:hgv=only_straight_on style matches the approved Conditional restrictions syntax. But because of an unresolved bug in some widely used software, it can lead to incorrect routing - restriction:hgv=only_straight_on is treated as if the relation was tagged restriction=no_*. As a result, some mappers use type=restriction:hgv + restriction=only_straight_on as a workaround.
  2. 2.0 2.1 2.2 2.3 The "from" and "to" members must start/end at the "via" node or the "via" way(s), otherwise split it!
  3. Notice: Processing of turn restrictions which contain one or more 'ways' in the via role is more complicated than if a single 'node' is used for the via role. As a result some routing software works only with turn restrictions that contain nodes in the via role. This should be fixed by the software, however if you have a straight choice whilst tagging the restriction, please consider using just a single node within the via role.
  4. RVV 1990, sign D7
  5. If tag restriction=only_left_turn wrongly prohibits u-turn in such crossing, where u-turn is allowed, we should use relations restriction=no_straight_on and restriction=no_right_turn instead.

See also

Tools