Prohibited transition on crossing

[Azbesciak]

Hi, first of all I think turn restrictions section needs to be improved; there is still old schema (road based property), also 'via' example is invalid (segments order, via segment via-turn-restriction-via is rather overture:transportation:example:simple-road2).

Also in general the data is quite poor - for the whole Berlin I have found only 16 simple prohibited turns.

To the point - assuming we have a crossing like below:

how to model prevention of the transition marked with the arrow?
From the schema description, I would assume Segment B would have prohibited transition to Segment A on connector 2.
All would be fine but then is it left turn or right turn?
So maybe a list of connectors there would be better?

[sanjibdutta1]

Assuming that the geometry orientation of the segments are forward i.e segment A (Connector1, Connector2, Connector3) and segment B (Connector5, Connector2, Connector4), the restriction would be modeled as a property on segment B like:

id: segment B
road:
  restrictions:
    prohibited_transitions:
      - sequence:
        - segment_id: segment A
          connector_id: Connector 2
        final_heading: forward
    when:
      heading: forward

When heading:forward will indicate south -> north travel on segment A and final_heading: forward means west->east travel on segment A and the restriction is on connector 2, so there is not ambiguity.

[Azbesciak]

Thank you. Yes, indeed no ambiguity, but also not the most user friendly if you need to map it

[sanjibdutta1]

Yes, its not very straight forward, but since we need to support linear referencing, we needed initial and final heading and an ordered sequence of (segment, connector) tuple.