Wider London c-charge mooted as road pricing bounces back
New tag tech makes paying easier, or maybe more frequent
London Mayor Ken Livingstone is secretly planning to roll congestion charging out across London, claims the Times , citing a source  "close to Mr Livingstone." Livingstone's manifesto for the upcoming mayoral election makes no mention of such a plan, but it does refer to a "new, hassle-free system for paying the congestion charge, which will enable drivers to choose to have payments automatically debited when they enter the charging zone."
This is the tag and beacon system that Transport for London has been testing. Such systems consist of roadside monitoring devices which pick up an ID from passing vehicles and charge accordingly. They're fairly widely used in tolling systems throughout the world, and although they could be used for charging for entry to areas such as the current London Congestion Charge zone (which recently magically transformed itself  into a low emissions zone), they also facilitate charging based on distance covered and the nature of the roads used. Tag and beacon systems still have to implement some form of enforcement mechanism, typically an Automatic Number Plate recognition system that logs vehicles that don't have valid tags, but they are inherently more flexible and potentially more pervasive than the ANPR monitoring used by the current congestion charge, which logs all vehicles going into the zone.
Plans for a road pricing scheme aimed at cutting congestion and/or emissions within the M25 area have existed for some years,  and technology trials of tag and beacon have investigated "how new technology could support more advanced congestion charging schemes, which might in future replace or supplement the existing approach" and systems based on "time of day, distance driven, specific roads, congestion levels etc" (TfL congestion charging technology report). TfL has also been concerned to make its future systems compatible with "technologies trialled with other national and European road charging initiatives." Coincidentally, in his budget statement today Chancellor Alistair Darling set aside new money for future national road pricing tests - national road pricing; the recent demise of national road pricing would therefore seem to have been remarkably brief.
Transport Secretary Ruth Kelly's alternative plans  for the rollout of smart road infrastructure do however, as The Register pointed out, facilitate the implementation of future road pricing systems based on - tag and beacon. ®