Traffic Congestion data capture techniques in the UK

Was wondering what are the various data capture techniques. On the
highways I notice there are a lot of cameras. Do these get used to
create and feed traffic data? Is this done in real time via some
traffic monitoring system? Or is the video just used for audio
broadcasts over the radio?

What about local roads? In London there are hotspots which form at
various times in the day but is there any real time data capture
techniques used here?

How do the various gps systems get their traffic information and has
anyone benchmarked which one is the best solution for this feature?

Any other relevant websites/forums that are more appropriate to find
out abou this?

Cheers
Hiro

There are two types of camera. The visual ones which are used for the likes
of radio stations and highways agency monitoring. And then there are the
trafficmaster type which read peoples numberplates to track their speed
between two points, and then use that to determine the current speed of
traffic flow.


Dunno, but often cameras etc are only on the major roads.

Some districts are experimenting with tracking cell phone velocities to map
traffic congestion.

On Fri, 17 Feb 2006 14:11:45 +0000, Marc Brett


How do they know whether a moving cell phone is inside a vehicle or
whether its being carried by a pedestrian or cyclist?

Chris

wrote:


Hard to say *exactly*, but if it travels through enough cells in a given time,
you can rule out pedestrians and all but the fastest cyclist. And if you have
enough cell phones, the odd pedestrian or cyclist becomes merely statistical
noise. I guess.