My landlord and good friend is chair of the Pigeon Key Association. There is
a two mile long one lane private bridge out to the key from the main highway
(If you seen the movie "True Lies - Arnold Schwarzenegger" you seen the
Presently, they allow traffic going out for the first 1/2 of the hour and
traffic going in for the last 1/2 of the hour. They are looking for a
traffic signal on each end of the bridge that would be green unless there is
I googled for a few places and sent Emails with no luck so far. Does anyone
know of a commercial company that could provide something like this? This
has to professional - its for hauling the public to and from the attraction.
Did you check with Crouse-Hinds? I'll bet they have already done this
exact system many times. They may even have a radio system so you don't
have to run 2 miles of wire. If you don't know the name, look at the
nearest traffic light to your house. It will almost certainly have
been made by them. They do all sorts of custom systems to handle
drawbridgs, etc. This is the base company http://www.crouse-hinds.com /
but they must have the traffic signals somewhere else.
I was going to suggest the same company- they are located in Syracuse,
NY- about 20 minutes from my house. I'm not sure how much longer
they'll be here- the parking lot is mighty empty and I've heard the
plant has less than 20 workers.
I'd talk to the local town or state highway department - ask advice - they might
have an old manual or relay one in junk - when they use solid state models now.
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder
Karl Townsend wrote:
I've replied to Karl. With a few ideas. Without knowing exactly the use,
WHO uses it (public or employees?) the proposed budget, and potential
liability issues, its a tough call.
BTW. Crouse Hinds hasn't made traffic signal equipment in years. :-)
An old CH rep relocated and dropped by our shop and gave me a brand new CH
signal head with ball cap visors. Pretty cool looking, it sits up on a
shelf in the shop.
On Wed, 8 Feb 2006 19:24:05 -0500, "Karl Townsend"
Have your friend contact the State Traffic Engineer in Tallahassee.
That office will know which vendors and suppliers of traffic control
equipment are currently considered viable. They will presumably also
be able to offer some advice on how to approach the problem. It's not
as simple as it might appear, but traffic engineers understand the
About any programmable four-phase or eight-phase actuated controller
could do this job. (This is only a two-phase situation, but there's
about no market for twophase controllers.) This is an unusual
situation for an actuated controller because of the rather long
clearance interval involved.
Issues to ask about:
Would an actuated control really work better than a fixed-time
controller in this situation.
Might a TOD/DOW programmable fixed-time controller work better than
present setup and/or an actuated controller
Recommended controller vendors and models. Preferred vendors in FL
may be different than those preferred in regions with fewer lightning
strikes per year.
Recommended loop sensor vendors and models
Should queue length sensing be provided on one or both ends
Recommendations for programming permissive phase timing as fns of
elapsed time in a permitted phase, time since last actuation, queue
lengths, etc etc.
I am not a traffic engineer, but I designed traffic controllers and
worked with traffic engineers (including those in Tallahassee and Dade
County), once upon a time.
Traffic engineers in general were panned recently on this NG. It's
like anything else: some are better and more motivated than others.
Some are genius good at tuning an intersection or stretch of arterial
to run smoothly with max volume and minimum delay. It ain't as
simple as it might appear. There are well over a hundred
user-adjustable variables in a fully-actuated 8-phase dual ring
controller. Things may (or may not) have progressed now to the
point where controllers employ AI and/or neural net logic to learn
from experience. I doubt that they have because it's a very
cost-competitive meet-the-spec low-bidder-win biz that doesn't
motivate R&D beyond cost reduction in design and mfg.
On Wed, 8 Feb 2006 19:24:05 -0500, "Karl Townsend"
Sounds to me like something homebrew is needed - they might make
something, but it's not going to be setup for that long a span between
the ends. They might make something to control a 100' tunnel, not two
Free-form idea dump - see if you can find any gems here.
To be really reliable, this needs to be preferably a wired system
between the two ends - an RF link would work, but it increases the
possible failure modes. Is there any communications cable or a vacant
conduit between the two points, preferably a telephone cable where you
can lease a few pairs?
It needs to have some 'smarts' and feedback between the two signal
light control stations at the ends. The system HAS to handshake
every status change between the two ends - you don't want it going
green at both ends.
And to keep track of the traffic if it's operating totally
"automagically" you might want those comm pairs available at a few
spots mid-span (along with a power source) so the electronics can
track the progress of the traffic with loop detectors, treadle
switches, or other means. (Optoelectronics is out due to fog and
birds.) You would count five vehicles entering the span, five at the
first mid-span check, three at the second mid-span check, three clear
the other end - hey, waitaminit...
A simple timed system is out, too easy for someone to stop along the
way. (Even if there are signs every 100 feet warning people not to
stop, some moron will.)
My vote would have two sets of off-the-shelf access control systems
and motorized gate arms at both ends, and multiple cars get a short
window (5 minutes) to get on as a batch, then it's the other
direction's turn. Call Stanley and see if they have parts you can use
to kit-bash into what you need.
Use a 'check code' system using off-the-shelf parking lot access
control equipment and some custom smarts to run them. They sell these
automated systems where the ticket reader reads the IN time on the
ticket and computes the payment - that IN time could just as easily be
a sequential serial number with a check digit.
People receive a code (ticket printer/spitter) to raise the arm and
get onto the bridge, and at the other end they enter the same code
(keypad or put the machine-readable ticket into a ticket receiver/
reader) to raise the exit gate arm and clear them across in the
computer. When all the vehicles in that direction's batch are
confirmed clear, allow the opposing flow. And if nobody's waiting, go
to 'first car either way gets the priority'. That can get goofed up
too, but it's less likely.
And you can have all the disclaimer crud printed on the back of the
ticket with the bridge rules (This Ticket Limits Our Liability...) so
they can't say you didn't warn them. ;-P
You may want an override so the local LEO or Fire/Ambulance
officials can override the timer and get priority the second the last
car clears. Or better, some sort of 'secret' control access phone
number so the police or ambulance dispatcher can preempt the bridge
timing the second the call goes out, and the green will be waiting for
the ambulance when they arrive.
--<< Bruce >>--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
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