I knew of the OpenStreetMap Routing Service before but it was only recently that I got to play around with it. It's a pretty nifty service and I've been trying out various routes within Metro Manila since I've pretty much driven most major streets in this metropolis and I wanted to cross-validate what I know with the service's algorithm and the OSM data.

As a result of my playing around, I've identified several major errors in the routing-related data in OSM (e.g., one direction of a dual-carriageway trunk bridge had a reversed oneway tag) and isolated a possible routing algorithm issue.

The Routing Service is definitely a must-have tool for verifying the OSM data (Maplint can only do so much). :-)