I'm am trying to define a data structure to represent road networks. The immediately obvious structure is that of a graph - a set of nodes and edges that connect pairs of nodes. The nodes would represent things like intersections, and the edges would represent lanes.
However, the basic concept of a graph is insufficient to describe what I want. I also want to be able to describe how certain lanes are "reachable" or "adjacent" to other lanes. (Imagine parallel lanes with no median between them. You can just switch lanes.) This seems to imply a need to have some sort of meta-edge that connects pairs of edges. Is there any mathematical structure that sounds like this? Is this reducible to the standard concept of a graph? Thanks.