lrk@k5qwb.lonestar.org (Lyn R. Kennedy) (04/19/91)
The Opticon units installed around here force the signal green
to clear out traffic. The red-all-directions scheme has a safety
fault: If it doesn't work, the emergency equipment may be racing
into an intersection while the cross-traffic has a green light and
the driver thinks it's red.
One posting mentioned a system truning the lights green both ways
when two emergency units approached from different directions. I
hope they fired the guy if this is true. Traffic lights are supposed
to have a safety device that monitors current to the opposing greens
and if both are on it shorts the power line, forcing the system to the
flashing mode.
I just wish the traffic idiotjineers could make the signals work
right without the extra goodies.
-------------------------------------------------------------------------
lrk@k5qwb.lonestar.org lrk@k5qwb.UUCP
73, utacfd.utarl.edu!letni!rwsys!kf5iw!k5qwb!lrk
Lyn Kennedy K5QWB @ N5LDD.#NTX.TX.US.NA
P.O. Box 5133, Ovilla, TX, USA 75154
-------- "We have met the enemy and they are us." Pogo -----------------bender@oobleck.Eng.Sun.COM (I want to be eating rich soup in another town) (04/20/91)
In article <N20L11w163w@k5qwb.lonestar.org> lrk@k5qwb.lonestar.org (Lyn R. Kennedy) writes:
->One posting mentioned a system truning the lights green both ways
->when two emergency units approached from different directions. I
->hope they fired the guy if this is true. Traffic lights are supposed
->to have a safety device that monitors current to the opposing greens
->and if both are on it shorts the power line, forcing the system to the
^^^^^^^^^^^^^^^^^^^^^^^^
really? you mean it literally shorts the 110VAC coming into the traffic
light controller? I assume then that some traffic engineer has to come by
and reset the controller??
->flashing mode.
mike
--
Won't look like rain, Won't look like snow, | DOD #000007
Won't look like fog, That's all we know! | AMA #511250
We just can't tell you anymore, We've never made oobleck before! | MSC #298726lrk@k5qwb.lonestar.org (Lyn R. Kennedy) (04/21/91)
bender@oobleck.Eng.Sun.COM (I want to be eating rich soup in another town) writes: > In article <N20L11w163w@k5qwb.lonestar.org> lrk@k5qwb.lonestar.org (Lyn R. Ke > ->One posting mentioned a system truning the lights green both ways > ->when two emergency units approached from different directions. I > ->hope they fired the guy if this is true. Traffic lights are supposed > ->to have a safety device that monitors current to the opposing greens > ->and if both are on it shorts the power line, forcing the system to the > ^^^^^^^^^^^^^^^^^^^^^^^^ > really? you mean it literally shorts the 110VAC coming into the traffic > light controller? I assume then that some traffic engineer has to come by > and reset the controller?? > > ->flashing mode. That's the way it was explained to me. I don't repair these things but it's supposed to have a basic controller to do the 'flash' mode and then another box to run the 'colors'. You can un-plug the controller and re-place it by putting the system on 'flash'. If the fuses to the controller blow, the switch to the 'flash' mode should occur. Since the 'opposing greens' is so dangerous, the safety device blows the fuses ( maybe breakers? ). ------------------------------------------------------------------------- lrk@k5qwb.lonestar.org lrk@k5qwb.UUCP 73, utacfd.utarl.edu!letni!rwsys!kf5iw!k5qwb!lrk Lyn Kennedy K5QWB @ N5LDD.#NTX.TX.US.NA P.O. Box 5133, Ovilla, TX, USA 75154 -------- "We have met the enemy and they are us." Pogo -----------------
rice@willow23.cray.com (Jonathan Rice) (04/23/91)
In article <N20L11w163w@k5qwb.lonestar.org> lrk@k5qwb.lonestar.org (Lyn R. Kennedy) writes: > The Opticon units installed around here force the signal green >to clear out traffic. The red-all-directions scheme has a safety >fault: If it doesn't work, the emergency equipment may be racing >into an intersection while the cross-traffic has a green light and >the driver thinks it's red. The gadget in use in St. Paul MN (don't know what brand it is) doesn't just switch the colored signals. In addition, a bright white spotlight, about 1/3 the diameter of the ordinary colored lenses, goes on in all four directions. These lights are mounted on a little mast above the signal. I had always thought that this was to prevent boneheads from deciding that the time was ripe for a right-on-red...but the quoted posting makes me think it might also serve as confirmation for the onrushing emergency vehicle. The scheme has another advantage: I often see the white light before I see flashers or hear a siren, and can prepare to pull over. -- Jonathan C. Rice | Internet: rice@cray.com | UUCP: uunet!cray!rice
adeboer@gjetor.geac.COM (Anthony DeBoer) (04/26/91)
In article <111016.10481@timbuk.cray.com> rice@willow23.cray.com (Jonathan Rice) writes: >The gadget in use in St. Paul MN (don't know what brand it is) doesn't just >switch the colored signals. In addition, a bright white spotlight, about 1/3 >the diameter of the ordinary colored lenses, goes on in all four directions. >These lights are mounted on a little mast above the signal. > >I had always thought that this was to prevent boneheads from deciding that >the time was ripe for a right-on-red...but the quoted posting makes me think >it might also serve as confirmation for the onrushing emergency vehicle. > >The scheme has another advantage: I often see the white light before I see >flashers or hear a siren, and can prepare to pull over. A third advantage is that it confirms that the emergency-vehicle-detector was tripped, and makes it a bit more obvious if some bonehead :^) is tripping it himself with a strobe in order to get to work faster. If people see the white lights go on and nothing unusual goes through the intersection, they're going to start to wonder. -- Anthony DeBoer NAUI#Z8800 | adeboer@gjetor.geac.com | Programmer (n): One who Geac J&E Systems Ltd. | uunet!geac!gjetor!adeboer | makes the lies the Toronto, Ontario, Canada | #include <disclaimer.h> | salesman told come true.
seanp@amix.commodore.com (Sean Petty) (04/27/91)
adeboer@gjetor.geac.COM (Anthony DeBoer) writes: > A third advantage is that it confirms that the emergency-vehicle-detector was > tripped, and makes it a bit more obvious if some bonehead :^) is tripping it > himself with a strobe in order to get to work faster. If people see the whit > lights go on and nothing unusual goes through the intersection, they're going > to start to wonder. Several people have made mention to the possibility of tripping these traffic lights with ordinary Radio Shack strobe lights going at about 16Hz... Could some authoritive source please tell me if this is really possible? You mean to tell me that all I need to do is buy a $40 strobe light and put it on my dash board to get all greens? C'mon! It HAS to be harder than that!! Sean ------- Sean Petty |INTERNET: undrground!seanp@amix.commodore.com | UUCP: uunet!cbmvax!amix!undrground!seanp "In order to make anything from | ICBM: 39.58.1' North 75.61.1' West scratch, you must first create | 50/50: seanp@undrground.UUCP the universe." - Carl Sagan | seanp@amix.commodore.com