From: Brian Kantor <brian@ucsd.edu>
Subject: Re: Emergency Highway Phones
Date: 7 Jun 91 21:02:04 GMT
Organization: The Avant-Garde of the Now, Ltd.

In article <telecom11.429.6@eecs.nwu.edu> decwrl!well.sf.ca.us!well!
dag@uunet.uu.net (Darren Alex Griffiths) writes:

> A local newscast reported on some interesting highway emergency phones
> this morning.  It seems that CalTrans is installing phones throughout
> the San Francisco bay area on major highways....

Yes, they are solar-powered cellphones.  When you open the door on the
phone box (a bright yellow weatherproof housing about a cubic foot or
so), the phone autodials the local CHP office on a special hunt group,
downline signals its identification code (which is mapped by a
computer at the CHP office to the location), and then cuts through to
voice so you can speak to the dispatcher or phone attendant, who will
take care of your problem or patch you through to someone who can.

That means that even if you can't make an intelligible noise, they'll
ask the beat patrol unit to stop by and check on a phone that's open,
so it's enough to stagger from the burning wreck, grab the door open,
then faint.

The phones also have other sensors to signal low battery [presumably
solar supply failure], tampering, tilt, or self-check diagnostic
failure.

I'm assuming the ones in SF are the same as the ones we've had here in
SoCal for a couple of years; they're manufactured here and just over
the border in Mexico by a division of Cubic Corp, and checked and
installed by their techs.

I'm told the phone number dialled, ident, and other such things are
burnt into a ROM in the phone controller which also holds the
software; apparently it's designed to make it difficult to use the
phone for any other purpose were you to liberate one from its roadside
loneliness.

[This is from a friend of mine who is a senior field install/repair
tech for these, and has travelled all over the state supervising
installations.  I didn't take notes but I think the previous
description is fairly accurate.]


Brian