Key:priority

Single lane traffic direction priority

Where traffic is narrowed to a single lane due to an obstacle such as a narrow bridge or a traffic calming measure there is sometimes a sign either side of the restriction indicating that one direction of traffic has priority over the other. These signs are registered in the  Vienna Convention on Road Signs and Signals as these:

• 

  Priority over oncoming traffic (B6)

• 

  Priority for oncoming traffic (B5)

It is useful to record this information in OpenStreetMap so that routing algorithms could take account of it in determining the delay based on travel direction.

Applies to: ways (typically highway=*) and nodes (typically traffic_calming=choker).

• Use priority=forward for priority in the same direction as a way's ordered set of nodes.
• Use priority=backward for priority in the opposite direction to a way's ordered set of nodes.

See also

• oneway=alternating - When the narrow section is controlled by traffic signals instead of priority signs
• priority_road=* - Signposted priority roads