[OSM-talk] Left and Right - a proposal

[Gervase Markham]

Stephen Gower wrote:
> I see from later posts that you also suggest using this scheme for cycle/bus
> lanes to indicate which side of the road they should be rendered.  

Did I?

> This
> highlighted to me a general problem with the scheme. For rendering the
> scheme is perfect - drawing a bus stop or a cycle lane on one side of a road
> is exactly what is needed.  However, for routing you need to know which
> direction a bike may travel along a cycle lane, or which direction buses
> from a stop will be heading.  To derive a travelling direction from the
> Left/Right terms a routing engine is usually going to need to know the local
> "rule of the road" - do we just leave this to the routing engine to factor
> in (needing to work out where in the world it is), or is there another
> simple solution I've missed.

Surely the routing engine needs to know this already, for example to
take you up or down the correct ramp at a motorway interchange?

Gerv