Handle `connectivity` relations and `placement` tags representing how lanes continue on the next road segment

[daniel-j-h]

@1ec5 just flagged the transit:lanes tag for us:

This proposal introduces the key and relation transit which allows to specify how a lane continues in the next road segment, i.e. if and where it forks/joins. It is intended to be used together with the suffixes :lanes, :forward or :backward.

https://wiki.openstreetmap.org/wiki/Proposed_features/transit https://wiki.openstreetmap.org/wiki/Key:turn#Motorway_with_links_and_destinations

At time of writing this there are roughly 2k way tags:

https://taginfo.openstreetmap.org/keys/transit%3Alanes

Could be useful not only for our lane handling code in pre-processing but e.g. for lane anticipation in post-processing.

cc @1ec5 @MoKob

[1ec5]

Relatedly, change and its variants are used 69,077 times worldwide to indicate where lane changes are allowed. That would be useful for determining where to place guidance about getting into a turn lane.

[daniel-j-h]

Ticket for lane change: https://github.com/Project-OSRM/osrm-backend/issues/3294

[1ec5]

Note that the transit proposal includes a transit relation scheme for linking a maneuver across an intersection, so it isn’t just a tag on a way.

[1ec5]

Note that the transit proposal includes a transit relation scheme for linking a maneuver across an intersection, so it isn’t just a tag on a way.

The proposed transit relation type has been rejected. In its stead, a distinct connectivity relation type has been approved and is in wide use.