Wildly wrong routing


I’ve been trying to debug a piece of mis-routing in my new routing code, only to find what seems to be a road that’s accidentally marked as being the wrong way for a one-way road.

Nothing surprising about that, you might say - but this road is at a MAJOR British junction. More precisely, it’s the M25 London orbital, and with that one-way road there it’s impossible to travel clockwise round it.

I tried to get history on the area to see if it was recent vandalism, but when I click the ‘History’ tab at the top, all I get are ‘(big), (big), (big)’ changes. How do I hide these irrelevant changes, so I can actually get the history for the area?

Is everyone who writes routing software also writing ‘fix the weird roads’ code that just looks for roads that suddenly change one-way direction halfway along them, and fixing them on the fly? Could this be applied to the OSM data so it’s more correct, rather than having loads of wrong-way-one-way roads on the map?

I fix not connected nodes, nodes that should not be connected at all and wrong oneways all the time as users report routing to be broken. Data errors are and will continue to be problems.

Regarding the history, you can select the way and have it’s personal history and see the difference between the various versions: Click on the way when the data layer is active and then click on Show History.

I find it curious that the section of M25 that I looked at is still at version 1…

Keep Right will warn of “dead-ended one-ways”, plus “almost-junctions” and various other things that will break routing. So its worth checking it and fixing errors in your area: http://keepright.ipax.at/