parnass@ihu1h.UUCP (Bob Parnass, AJ9S) (05/10/86)
x
Spoofing Traffic Lights
Here's the scenario:
I'm stopped at an intersection, waiting for the light
to turn green. No one else is around. The light seems
to be red for an eternity, but there's no traffic.
I back my truck up a few feet, off the sensor loop buried
in the roadway, then drive back over the loop a few
times. This will usually cause the traffic signal to
become green.
--
===============================================================================
Bob Parnass, Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414jimb@drutx.UUCP (Jim Bryant) (05/10/86)
In article <840@ihu1h.UUCP> parnass@ihu1h.UUCP writes: > Here's the scenario: > I'm stopped at an intersection, waiting for the light > to turn green. No one else is around. The light seems > to be red for an eternity, but there's no traffic. > I back my truck up a few feet, off the sensor loop buried > in the roadway, then drive back over the loop a few > times. This will usually cause the traffic signal to > become green. if there's no traffic, i just go on through :-) at&t information systems/denver colorado/jim bryant - k6 ...!{ihnp4,ulysses,mtuxo,pegasus,whuxl}!drutx!jimb -- le mieux est souvent l'ennemi du bien
jawa@ihuxl.UUCP (James A. Wadas) (05/12/86)
> x > Spoofing Traffic Lights > > Here's the scenario: > > I'm stopped at an intersection, waiting for the light > to turn green. No one else is around. The light seems > to be red for an eternity, but there's no traffic. > > I back my truck up a few feet, off the sensor loop buried > in the roadway, then drive back over the loop a few > times. This will usually cause the traffic signal to > become green. > -- > =============================================================================== > Bob Parnass, Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414 Photovoltaic cells sometimes react when you "flash your brights" on an upcoming traffic signal so equipped. Deserted intersections at twilight provide the best conditions for this phenomenon. -- James Wadas @ AT&T Bell Laboratories -- Naperville, Illinois (312) 979-0240 ...!ihnp4!ihuxl!jawa
john@anasazi.UUCP (John Moore) (05/14/86)
In article <840@ihu1h.UUCP> parnass@ihu1h.UUCP (Bob Parnass, AJ9S) writes: >x > Spoofing Traffic Lights > > Here's the scenario: > > I'm stopped at an intersection, waiting for the light > to turn green. No one else is around. The light seems > to be red for an eternity, but there's no traffic. > > I back my truck up a few feet, off the sensor loop buried > in the roadway, then drive back over the loop a few > times. This will usually cause the traffic signal to > become green. I use this trick all the time. It works most of the time - especially in a left turn lane. I think it is technically illegal to back up in a traffic lane, however. -- John Moore (NJ7E/XE1HDO) {decvax|ihnp4|hao}!noao!terak!anasazi!john {hao!noao|decvax|ihnp4|seismo}!terak!anasazi!john terak!anasazi!john@SEISMO.CSS.GOV (602) 861-7607 (day or evening) 7525 Clearwater Pkwy, Paradise Valley, AZ, 85253 (Home Address) The opinions expressed here are obviously not mine, so they must be someone else's.
cem@intelca.UUCP (Chuck McManis) (05/15/86)
> > Photovoltaic cells sometimes react when you "flash your brights" > on an upcoming traffic signal so equipped. Deserted intersections > at twilight provide the best conditions for this phenomenon. > James Wadas @ AT&T Bell Laboratories -- Naperville, Illinois Yes and some have photovoltaics "tuned" to the stroboscopic frequency of emergency vehicles. This allows the light in front of a fire truck to change for it, thus speeding up response time. --Chuck -- - - - D I S C L A I M E R - - - {ihnp4,fortune}!dual\ All opinions expressed herein are my {qantel,idi}-> !intelca!cem own and not those of my employer, my {ucbvax,hao}!hplabs/ friends, or my avocado plant. :-}
bill@hp-pcd.UUCP (bill) (05/15/86)
OK, so setting traffic lights aside, can you tell me how to trigger
a railroad crossing? A friend of mine claims that he once did it by
shorting the two rails together near the crossing with a piece of heavy
wire ...
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hp-pcd!billsaba@ihlpl.UUCP (Sabalaskey) (05/19/86)
> > OK, so setting traffic lights aside, can you tell me how to trigger > a railroad crossing? A friend of mine claims that he once did it by > shorting the two rails together near the crossing with a piece of heavy > wire ... Yes, this works fine. The wheels of the train short the two rails together and cuase the gates/lights to operate. You dont even need a heavy wire, a plain lamp cord (18 guage) will do fine. PS: I found this out at about when I was 12 years old while I was learning about elctrical theory. I always did wonder how the gates knew that the train was coming. I reaked havoc for I while when I found out how to bring the gates down without having a train go by (until the neighbors saw me, that is!!!!) Bruce Sabalaskey ihnp4!ihlpl!saba
larry@kitty.UUCP (Larry Lippman) (05/20/86)
In article <37700004@hpcvlo.UUCP>, bill@hp-pcd.UUCP (bill) writes: > > OK, so setting traffic lights aside, can you tell me how to trigger > a railroad crossing? A friend of mine claims that he once did it by > shorting the two rails together near the crossing with a piece of heavy > wire ... Yup, that will trigger the railroad crossing signal. It requires a fairly low resistance path (i.e., a good connection) to trigger a track signal, since the signal must be immune to wet weather conduction, and the track relay is therefore not very sensitive. I wouldn't recommend making a habit of doing this, since it might be a bit upsetting to the railroad, as the signal operation might be interpreted as a "train" in the particular block of track. ==> Larry Lippman @ Recognition Research Corp., Clarence, New York ==> UUCP {bbncca|decvax|rocksanne|rocksvax|watmath}!sunybcs!kitty!larry ==> VOICE 716/688-1231 {rice|shell}!baylor!/ ==> FAX 716/741-9635 {G1, G2, G3 modes} seismo!/ ==> "Have you hugged your cat today?" ihnp4!/
henry@utzoo.UUCP (Henry Spencer) (05/21/86)
> OK, so setting traffic lights aside, can you tell me how to trigger > a railroad crossing? A friend of mine claims that he once did it by > shorting the two rails together near the crossing with a piece of heavy > wire ... Sounds plausible. The way a train makes itself known to railroad switching systems is that its wheels and axles constitute a short between the two rails. Note that triggering railroad crossing lights and gates is not the full extent of the effect, since it will show up as a phantom train for signalling and control purposes as well. I suspect the railroad would not be amused, especially if another train had to make a panic stop because the control system suddenly "saw" a "train" in the section ahead of it. -- Join STRAW: the Society To Henry Spencer @ U of Toronto Zoology Revile Ada Wholeheartedly {allegra,ihnp4,decvax,pyramid}!utzoo!henry
todd@mit-amt.MIT.EDU (Hisashi Todd Fujinaka) (05/21/86)
I just wanted to point out that it is VERY ILLEGAL to mess with RR crossing signals. It is done by shorting out the tracks, and there are several insulated sections of track on each side of the crossing so the signal can tell which way the train is going, if the train is stopped near the crossing, etc. It varies from crossing to crossing, but the standard crossing does have some RRL (relay to relay logic :->) to tell which way the train is going. On the illegality note, remember if you screw it up and people die, you've just committed MURDER. Trains are big and fast and kill people. Actually, trains don't kill people: people kill people. Enough of that. Todd