[aprssig] Traffic Speed Monitoring?
Stephen H. Smith
wa8lmf2 at aol.com
Sat Nov 12 14:33:21 CST 2011
On 11/12/2011 2:52 PM, Bob Bruninga wrote:
> I just realized how tribvial it is for the state to gather traffic speed. THey just put EZPASS detectors on underpasses and then keep track of how long it take any given ID to go from one detector to the next.
> Is this how they do it?
Not mostly. You must not get out of eastern areas laced with toll roads
much.... In most of the country, without many toll roads, people just don't
have the EzPass transponders.
In California, it's thousands of induction sensors embedded in the pavement
detecting the passage of metallic masses moving over.
> I had heard they used cell phones
The commercial traffic services such as TMC (that supply the real-time traffic
data to car GPS devices over FM subchannels) use cell phone traffic to some
degree, but I don't think official government highway agencies do much.
> , ut I think the EZ pass woiuld be more straight forward...
> Bob, WB4APR
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