Dave Winer discovers a better route than the directions suggested by Google Maps, and wonders: “So — when does mapping become a two-way app? I’d be willing to tell their software that I have a better route, it’s one that comes from living here, and being a cab driver here.”

User-submitted directions look like one of those ideas that are brilliant in theory, but you can’t figure out a way to make them work in practice. There are, I think, two problems with it. One is mediating competing directions: how do you adjudicate between two alternate routes, each provided by locals who swear by them? (I can usually figure out several ways of getting from A to B; figuring out which is best is a bit harder.) The other is that there are simply too many different A and B points to navigate between: it’s one thing to know the best route between towns, or even between neighbourhoods, but how granular would user submissions be allowed to get?

It wouldn’t surprise me if driving directions were procedurally generated rather than stored in a database, in which case most of the errors would occur when real roads don’t match up with the algorithms’ expectations. But that’s just a wild guess on my part.

Previously: Tele Atlas Introduces Map Feedback.