OpenStreetMap
In the 8 years of OpenStreetMap, it is extraordinary that London’s Congestion Charging zone has not been properly mapped. Some road navigation systems are now using OpenStreetMap - the absence of the Congestion Charging zone on OSM means that some drivers are accidentally driving into the zone without being aware of the £10-a-day cost.
To bridge the gap, I am gradually adding “toll=yes” to affected roads as an interim measure, but in the long term we will need a dedicated standard tag to indicate the Congestion Charge zone because the Congestion Charge does not apply to pedestrians, cyclists, taxis, TfL buses and motorcyclists. I feel that a dedicated tag is necessary because I note that there are similar schemes in the world, including Milan, Singapore, Stockholm and Durham.
Contributors are invited to [discuss the future of mapping the Congestion Charge] (http://wiki.openstreetmap.org/wiki/London_Congestion_Charge) on OpenStreetMap. I think that OpenStreetMap is no longer a map just for cyclists and pedestrians, but for just about everyone.
Discussion
Comment from smsm1 on 1 March 2013 at 00:26
I would have thought it would have been better to map the congestion charge zone in London as an area, which I thought it was at one point.
Comment from ika-chan! UK-USA on 1 March 2013 at 00:31
So far, I am not aware if I can create “toll:motor_vehicle=yes” as a relation.
Comment from Jean-Marc Liotier on 1 March 2013 at 10:49
It is a “zone”… So why doesn’t any of the proposed modeling scheme in http://wiki.openstreetmap.org/wiki/London_Congestion_Charge represent it as such, using an area ? Wouldn’t that be simpler than tagging ways ?
Comment from Jean-Marc Liotier on 1 March 2013 at 10:53
Of course, tagging the “zone” as an area means that navigation tools will need to be area-aware - or that the Openstreetmap extract they use will require post-processing to tag any way within the area.
Comment from Tom Chance on 1 March 2013 at 11:47
Ideally you would have an area for the boundary and all the roads inside it bundled together into a relation, which carries the info on the price, operator, etc. otherwise it will be a bit of a pain updating it each time the details change!
Comment from ika-chan! UK-USA on 1 March 2013 at 11:59
If a relation was boundary-based like how the boroughs are done then we would have an issue at, for example, Hyde Park Corner where the A4 underpass is part of the zone but the roundabout that carries the Inner Ring Road above it is not. What I have done this morning is create a relation-based prototype which associates affected ways. It can be found at http://www.openstreetmap.org/browse/relation/2792532.