BBC News : Congestion charges face legal challenge

[Alison Wheeler]

David Hansen wrote on 17 July 2002 17:03
     Setting up a cordon is not something that is difficult, they have
     been doing it in Oslo for years (though with manual/machine)
     collection of the tolls.

automatic / remote for taxis in my experience ...

An additional camera that people haven't discussed btw. is the trafficmaster
'blue post' cameras on most trunk routes which, AIUI, 'read' the licence
plate info of every vehicle into a database then searches for where it was
last seen and calculate speed of traffic. ISTR that they said (when it was
introduced) that they couldn't (wouldn't?) inspect the database manually to
track or locate a specific vehicle.

The London system dumps all 'matched' data at the end of the day, and as the
entry points are (almost) all off the inner ring road it will be pretty
clear that you are 'on your way in' alongside the fact you are driving under
a gantry!

Alison