If you're a taxi driver planning a route, it might be preferable to approach a waypoint on the side of the road that deposits/picks up your passenger without needing to cross the road, and then continue routing you without issuing a u-turn.

This is partly implemented by the "allow u-turns at waypoints" parameter in the Lua profiles.

We could implement a query-time parameter called "keep waypoints on the left/right". When constructing phantom nodes, we would eliminate edges that do not put the foot segment on the specified side. The behaviour would be similar to the bearing filter - only the relevant edges would be seeded on the query heap.

It should be a query-time parameter to allow for left/right side driving, allowing localized apps to specify the desired side.