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 on OpenStreetMap. I think that OpenStreetMap is no longer a map just for cyclists and pedestrians, but for just about everyone.