"Nik-thevoice" wrote in message
...
On Wed, 11 May 2005 07:53:02 +0100, "Vernon"
wrote:
When LBC Travel News talk of travel information derived from "Satellite
Data", what sort of satellite help are they getting? I am aware of GPS
for
navigation, but I can't see how that could help with determining the
levels
of realtime traffic problems.
Just curious, but does anyone here know?
Knowing them (& the "radio travel news" world) as I do, Yes...I can
tell you.
1: Trafficmaster sensor readings - the blue poles by the side of the
road. www.trafficmaster.net
2: A system run by ITIS called TAG, although I'm not sure whether
they've started using this. Rough system diagram at
http://www.itisholdings.com/ourtech.asp
3: Highways agency "RTT" system - Induction loops in the road surface.
Google it, there's a "non professional" version online somewhere.
All of these, combined with your other information sources can build
up a good picture of what's happening.
Thanks Nik, I suspect that you have come up with the answer with TAG. I was
not aware of this system (I don't have the sort of car that is worth such
protection!)