Go Back  Bike Forums > Bike Forums > Living Car Free
Reload this Page >

Triggering Stoplights

Notices
Living Car Free Do you live car free or car light? Do you prefer to use alternative transportation (bicycles, walking, other human-powered or public transportation) for everyday activities whenever possible? Discuss your lifestyle here.

Triggering Stoplights

Old 11-30-10, 10:54 AM
  #1  
nostalgic
Senior Member
Thread Starter
 
nostalgic's Avatar
 
Join Date: Nov 2008
Location: USA
Posts: 109
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Triggering Stoplights

This topic has been visited before, but I couldn't find the thread, so here we go again.

On my way to the university, there are two major intersections I have to cross. The first one has a stoplight that either seems fairly easy to trigger, or is set to change no matter the traffic density, but not the second. I remember reading that there is a way to trigger stoplights without the help of cars and without pushing the pedestrians' walk button, but cannot remember what that is.

Correct me if I'm wrong, but is there a way?
nostalgic is offline  
Old 11-30-10, 11:55 AM
  #2  
adamrice
mosquito rancher
 
adamrice's Avatar
 
Join Date: Oct 2009
Location: Austin TX USA
Posts: 657

Bikes: Bob Jackson 853 Arrowhead; Felt VR30; Kinesis UK RTD

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 102 Post(s)
Liked 61 Times in 45 Posts
If you can't trigger the light, treat it as broken and ride through when safe.

Sometimes people with steel bikes can trigger some balky sensors by laying their bikes down directly over the cuts in the pavement
adamrice is offline  
Old 11-30-10, 12:54 PM
  #3  
Grishnak
Senior Member
 
Grishnak's Avatar
 
Join Date: Jan 2010
Location: West Sussex
Posts: 284

Bikes: Ridgeback Steel Tourer,Recumbent SWB,Steel Road,,Raleigh Twenty,Elephant Bike,Pashley Pronto TNT.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
On the instructables site,is a how to trigger the lights article.I think they used a neodymium magnet.
Grishnak is offline  
Old 11-30-10, 01:29 PM
  #4  
nostalgic
Senior Member
Thread Starter
 
nostalgic's Avatar
 
Join Date: Nov 2008
Location: USA
Posts: 109
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks.

Do neodymium magnets need to be as close to the ground as possible, or can they be placed elsewhere, such as in your front or rear basket?
nostalgic is offline  
Old 11-30-10, 01:48 PM
  #5  
Spudd
Senior Member
 
Spudd's Avatar
 
Join Date: Jun 2010
Location: Toronto, ON
Posts: 257

Bikes: Norco VFR D3, CCM Cruiser

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I don't know if the magnet thing works, but if it does, I would think it would need to be as close to the ground as possible. Here in Toronto they're starting to paint dots on the ground that indicate where you need to place your bike to trigger the light, which is nice.
Spudd is offline  
Old 11-30-10, 01:58 PM
  #6  
prathmann
Senior Member
 
Join Date: Nov 2008
Location: Bay Area, Calif.
Posts: 7,239
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 659 Post(s)
Likes: 0
Liked 3 Times in 2 Posts
Most traffic sensors (at least in the US) are induction-loop types that work the same as the metal detector devices people use at the beach to find coins and jewelry. They use a high frequency electric current in loops just under the pavement. Any nearby metal absorbs some of the energy of the resulting field and this is what triggers the light. No need for any of the metal to be iron or steel, so a bicycle with aluminum rims should be detectable. *BUT* this depends on how high the sensitivity is set on the detector. Many cities just set them high enough to detect cars and trucks which causes problems for cyclists (and some motorcyclists as well).

First make sure you're positioning your bike directly over the sensor location. If the pavement cuts are visible then place your wheel directly over the middle cut (or along an edge is it's a single loop pattern). Hidden loops after a repaving make it more difficult, but the loop is usually directly behind the stop line and in the middle of the lane. If it still doesn't respond then treat it as a broken signal (i.e. proceed when safe after being at a full stop) and contact your local transportation department with a request to adjust the sensor for higher sensitivity. In our area they will come out quite promptly to readjust sensors
prathmann is offline  
Old 11-30-10, 02:16 PM
  #7  
Shimagnolo
Senior Member
 
Shimagnolo's Avatar
 
Join Date: May 2008
Location: Zang's Spur, CO
Posts: 8,935
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 2421 Post(s)
Liked 2,102 Times in 1,086 Posts
https://www.humantransport.org/bicycl.../detection.htm

https://www.humantransport.org/bicycl...nals/green.htm
Shimagnolo is offline  
Old 11-30-10, 02:34 PM
  #8  
Fizzaly
Stealing Spokes since 82'
 
Fizzaly's Avatar
 
Join Date: Jan 2010
Location: Boy-z, Ideeeho
Posts: 1,875

Bikes: The always reliable kuwie

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by prathmann View Post
Most traffic sensors (at least in the US) are induction-loop types that work the same as the metal detector devices people use at the beach to find coins and jewelry. They use a high frequency electric current in loops just under the pavement. Any nearby metal absorbs some of the energy of the resulting field and this is what triggers the light. No need for any of the metal to be iron or steel, so a bicycle with aluminum rims should be detectable. *BUT* this depends on how high the sensitivity is set on the detector. Many cities just set them high enough to detect cars and trucks which causes problems for cyclists (and some motorcyclists as well).

First make sure you're positioning your bike directly over the sensor location. If the pavement cuts are visible then place your wheel directly over the middle cut (or along an edge is it's a single loop pattern). Hidden loops after a repaving make it more difficult, but the loop is usually directly behind the stop line and in the middle of the lane. If it still doesn't respond then treat it as a broken signal (i.e. proceed when safe after being at a full stop) and contact your local transportation department with a request to adjust the sensor for higher sensitivity. In our area they will come out quite promptly to readjust sensors
+1 Im pretty sure the sensors are the same as my company uses in parking garages and they are exactly as you described, I personally have found using the corners to be the best method of getting them to trip.
Fizzaly is offline  
Old 11-30-10, 04:11 PM
  #9  
mikeybikes
Senior Member
 
mikeybikes's Avatar
 
Join Date: May 2009
Location: Edgewater, CO
Posts: 3,214

Bikes: Tons

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
If you're not able to trigger it after trying suggestions, contact the local dept of transportation and ask them to calibrate it. I've been successful in getting a dozen or so calibrated. The only one that was never calibrated was torn down two weeks after I called. So, go figure.
mikeybikes is offline  
Old 11-30-10, 04:38 PM
  #10  
sauerwald
Senior Member
 
Join Date: Apr 2006
Location: San Jose, CA
Posts: 1,840

Bikes: Bianchi San Remo - set up as a utility bike, Peter Mooney Road bike, Peter Mooney commute bike,Dahon Folder,Schwinn Paramount Tandem

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Fizzaly View Post
+1 Im pretty sure the sensors are the same as my company uses in parking garages and they are exactly as you described, I personally have found using the corners to be the best method of getting them to trip.
+1 I am an electrical engineer, and prathmann gave a very good description of how most of the detectors work. They are most sensitive to loops of conductive material, and bicycle rims are usually the best things to trigger them. Place your wheel along the line of the pavement cut to get maximum results. If you have a carbon fiber bike, with carbon rims (you need to get your head examined), but one trick that you can use is to put a loop or two of copper wire or tape inside the tire, under the tube.

Random thought - how many Car-Free folk ride carbon fiber bikes?
sauerwald is offline  
Old 11-30-10, 05:03 PM
  #11  
chewybrian 
"Florida Man"
 
chewybrian's Avatar
 
Join Date: Mar 2008
Location: East Florida
Posts: 1,665

Bikes: '16 Bob Jackson rando, '66 Raleigh Superbe, 80 Nishiki Maxima, 07 Gary Fisher Utopia, 09 Surly LHT

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1275 Post(s)
Liked 757 Times in 425 Posts
What I want to know is, what is the signal to the driver behind me, to please pull up to trigger the light? The one light that gives me trouble is on my afternoon commute, in heavy traffic, and will not trip for me. I can pull up far enough that the car behind *could* trigger the light. But, whatever signals I give, pointing to the ground, and then the light, I get only blank stares from the confused motorist behind me.

Many times, a right on red is just as easy, depending on your heading, and that's my usual answer. But, in that case, it would mean a long run the wrong way, or a u-turn in crazy traffic.
__________________
Campione Del Mondo Immaginario
chewybrian is offline  
Old 11-30-10, 05:27 PM
  #12  
Fizzaly
Stealing Spokes since 82'
 
Fizzaly's Avatar
 
Join Date: Jan 2010
Location: Boy-z, Ideeeho
Posts: 1,875

Bikes: The always reliable kuwie

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
There are a few in my area that don't have signals, they are on timers but in boise cyclists only have to come to a stop and can proceed through (if clear that is) so in my morning rides (5:30am) i generally come to a rolling stop anyways as there usually isn't any cars to be seen.
Fizzaly is offline  
Old 11-30-10, 05:47 PM
  #13  
Archergal
Member
 
Join Date: Nov 2010
Posts: 33
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by chewybrian View Post
What I want to know is, what is the signal to the driver behind me, to please pull up to trigger the light?
I have a lot of cars that stop about 2 car lengths BEHIND me at lights like this. O_o I usually just motion them forward with a big smile, and then point to the ground and the light. Sometimes when I motion them forward, they just look confused. I just smile & nod and keep motioning. Then they usually move up.

Sometimes if they look friendly & I feel chatty, I'll tell them about tripping the light signal.

I only have one light on my regular routes that I can trip with any regularity all by myself.
Archergal is offline  
Old 11-30-10, 07:33 PM
  #14  
gerv 
In the right lane
 
gerv's Avatar
 
Join Date: Dec 2005
Location: Des Moines
Posts: 9,565

Bikes: 1974 Huffy 3 speed

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 43 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Thanks for these links.

The second link summarizes the issue pretty well. There are 3 types of sensor. The most common in my city is the inductive loop sensor. You need to get your wheel to cover as much of it as you possibly can. Normally here the sensors are shaped as hexagons, but the technique is the same... shoot for a section and cover as much as you can.

One thing to note is that, depending on the sensitivity of the light, it may never trigger without a 3000 lb can on top of it. Motorcycles will be left idling at the light, as well as bicycles.

In that case, consider calling your city and telling them you'll be soon forced to run red lights. Don't get off the bike and trigger the walk button... this makes it difficult and even dangerous to get back in the lane. Instead, tell your city to get it fixed for you.
gerv is offline  
Old 11-30-10, 07:48 PM
  #15  
wahoonc
Membership Not Required
 
wahoonc's Avatar
 
Join Date: Jan 2005
Location: On the road-USA
Posts: 16,855

Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
Likes: 0
Liked 6 Times in 5 Posts
Originally Posted by gerv View Post
Thanks for these links.

The second link summarizes the issue pretty well. There are 3 types of sensor. The most common in my city is the inductive loop sensor. You need to get your wheel to cover as much of it as you possibly can. Normally here the sensors are shaped as hexagons, but the technique is the same... shoot for a section and cover as much as you can.

One thing to note is that, depending on the sensitivity of the light, it may never trigger without a 3000 lb can on top of it. Motorcycles will be left idling at the light, as well as bicycles.

In that case, consider calling your city and telling them you'll be soon forced to run red lights. Don't get off the bike and trigger the walk button... this makes it difficult and even dangerous to get back in the lane. Instead, tell your city to get it fixed for you.
I have been in some places where the walk lights didn't work either.

If I cannot trigger the light in one cycle I will ride through it and report it.

Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(

ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.

"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"
_Nicodemus

"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"
_krazygluon
wahoonc is offline  
Old 11-30-10, 08:29 PM
  #16  
Shimagnolo
Senior Member
 
Shimagnolo's Avatar
 
Join Date: May 2008
Location: Zang's Spur, CO
Posts: 8,935
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 2421 Post(s)
Liked 2,102 Times in 1,086 Posts
Originally Posted by wahoonc View Post
I have been in some places where the walk lights didn't work either.
aka the "placebo button".
I have even encountered a light that had the button programmed as a placebo button during the day, but if pressed before 6am it gave an immediate green light.
Shimagnolo is offline  
Old 12-01-10, 01:57 AM
  #17  
bragi
bragi
 
bragi's Avatar
 
Join Date: Jun 2006
Location: seattle, WA
Posts: 2,911

Bikes: LHT

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
The city of Seattle has been nice enough to paint a little "T" over the spot that is most likely to trigger a traffic light at many intersections. I've noticed that my wheels don't trigger the signal nearly as effectively as my bottom bracket; but then, I ride a fairly heavy steel touring bike. At intersections that don't seem to work with bicycles, I either treat it like a malfunctioning signal and run the light if traffic is sparse, or use the pedestrian signal.

But honestly, unless it's very late at night, there is enough car traffic in the city that I don't need to worry about tripping signals; there's usually a huge massive car or SUV around to do it for me.
bragi is offline  
Old 12-01-10, 01:22 PM
  #18  
Roody
Sophomoric Member
 
Roody's Avatar
 
Join Date: Jan 2005
Location: Dancing in Lansing
Posts: 24,221
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 711 Post(s)
Liked 4 Times in 4 Posts
My problem is that I'm too impatient. I'll wait about 15 seconds over the loop, then figure it's broken and run the light. Then I'll look back over my shoulder and see that it's already green.
__________________

"Think Outside the Cage"
Roody is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jskash
General Cycling Discussion
30
12-09-15 11:00 PM
____asdfghjkl
Commuting
32
12-02-12 06:53 PM
Cyclomania
General Cycling Discussion
32
07-25-11 04:29 PM
Digital_Cowboy
Advocacy & Safety
26
04-07-10 02:51 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.