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Traffic Lights
Posted: Sat Apr 27, 2013 7:06 pm
by mikesbytes
I recently read an article about cyclists who ran red lights. The part of the article that got me was about cyclist who ran red lights where they couldn't trip the lights, implying that it was partially BS.
Yesterday I was waiting at a light sitting in the correct position to be detected (I could see the lines in the tarmac) and it went thru 2 complete sequences without detecting me.
To make matters worst, a car rolled up behind me, but rather than sitting the normal distance behind me, it sat way back, too far to provide detection. I've seen this many times, it seems that a small % of motorists like to exhibit extra perceived safety around cyclists, a pity that not all are like them but it doesn't help with cycle unfriendly lights.
Re: Traffic Lights
Posted: Sat Apr 27, 2013 7:21 pm
by trailgumby
One of the reasons I will sit in front of the white line in the ped x area when the intersection is unlikely to be busy with peds. Technically illegal, yes, but having car drivers being comforrtable with coming up to the line helps trip the lights in all our favour more quickly. Also helps me feel less vulnerable to being hit from behind by someone coming up to the lights.
Re: Traffic Lights
Posted: Sat Apr 27, 2013 7:35 pm
by Matt_Matt
Mike, grab a rare earth magnet and glue it to the sole of your shoe.
Matt
Re: Traffic Lights
Posted: Sat Apr 27, 2013 8:10 pm
by find_bruce
Matt_Matt wrote:Mike, grab a rare earth magnet and glue it to the sole of your shoe.
Do you have a lucky rabbit's foot to go with that - you have a common misunderstanding as to how the induction loop used on the majority of roads works
Re: Traffic Lights
Posted: Sat Apr 27, 2013 9:38 pm
by pacra
I go thru a quiet intersection 5 times a week. Up to a month ago it would trip within 20 seconds, now nothing. On the rare occasions a car comes in behind it trips almost immediately.
As I am on a steel frame I spoke to VicRoads ; I was given the mirror trick (they look into it).
As it relies on a changing magnetic flux nothing has changed regards the bike and I was told the sensitivity is preset. Cars still trip it so what/how/why has changed? Go figure.
Solution. Change route.
Re: Traffic Lights
Posted: Sat Apr 27, 2013 10:14 pm
by Tornado
I have a few in the early hours that won't change and cars are few and far between at 4-5am on my route. I just treat the red lights like stop signs. Stop, give way and get going. Otherwise I could sit there for half hour some days I'm sure.
Re: Traffic Lights
Posted: Sun Apr 28, 2013 5:52 am
by Matt_Matt
find_bruce wrote:Matt_Matt wrote:Mike, grab a rare earth magnet and glue it to the sole of your shoe.
Do you have a lucky rabbit's foot to go with that - you have a common misunderstanding as to how the induction loop used on the majority of roads works
That's it ... ?
Help me out, increase the inductance and the signals change ?
Matt
Re: Traffic Lights
Posted: Sun Apr 28, 2013 7:29 am
by bychosis
I heard the author speaking about the findings on the radio recently. Sounded as though most of those surveyed indicated they had a decent reason, ie lights won't change. I don't think it really addressed the main issue of perception of crazed rider flying through red lights without looking that gives cyclists a bad name. I didn't hear the whole interview though, it was background noise while otherwise occupied - I'm male, so can't do two things at once.
Re: Traffic Lights
Posted: Sun Apr 28, 2013 8:05 am
by Red Rider
The other week I waited at a set of busy lights with a button press, after two cycles without a turn I had to negotiate it on red. FYI the western side of Vincent St under the freeway in Leederville.
Have also not been detected numerous times outside the church at the start of Aberdeen St in Northbridge.
I read the article on
The Conversation, I think it wasn't bad, but it missed one of the biggest reasons cyclists run red lights; because it saves time. And I don't have a problem with it, because a bicycle is a vastly different vehicle to a car/bus/truck that treating them the same is ludicrous and motor vehicle drivers are just jealous their mode of transport isn't so agile and safe for other road users.
Re: Traffic Lights
Posted: Sun Apr 28, 2013 8:51 am
by find_bruce
Matt_Matt wrote:find_bruce wrote:Matt_Matt wrote:Mike, grab a rare earth magnet and glue it to the sole of your shoe.
Do you have a lucky rabbit's foot to go with that - you have a common misunderstanding as to how the induction loop used on the majority of roads works
That's it ... ?
Help me out, increase the inductance and the signals change ?
Matt
Nope - it works by detecting a
decrease in inductance
wikipedia wrote:When a vehicle passes over the loop or is stopped within the loop, the vehicle induces eddy currents in the wire loops, which decrease their inductance. The decreased inductance actuates the electronics unit output relay or solid-state optically isolated output, which sends a pulse to the traffic signal controller signifying the passage or presence of a vehicle.
The source for this is the US Department publishes a Transport Traffic Detector Handbook, where
chapter 2 sets out how inductive loop detectors work, including this
However, the ferromagnetic effect produced by the iron mass of the engine, transmission, or differential does not create a presence or passage indication by the controller. When the heavy ferrous engine enters the inductive loop's detection area, it increases the inductance of the wire loop. This effect occurs because the insertion of any iron core into the field of any inductor reduces the reluctance (i.e., a term that corresponds to the resistance of a magnetic circuit) of the flux path and, therefore, increases the net inductance. However, the peripheral metal of the vehicle has an opposite effect on the inductance due to eddy currents that are produced. The decrease in inductance from the eddy currents more than offsets the increase from the ferrous mass of the engine, and the net effect is an overall reduction in the inductance of the wire loop.
So if your magnet had any effect, it would be to reduce the possibility of you being detected.
Re: Traffic Lights
Posted: Mon Apr 29, 2013 12:45 pm
by duncanm
Silly thing about this is that I sometimes filter to the lights in a bus lane and accidentally trip the bus light!
My understanding was that the rules let you proceed through a red if it was clear that they weren't functioning correctly (eg: you'd sat through two sequences without a green or similar).
here it is: NSW road rules. Of course the onus is on you to prove they were not functioning correctly.
63 Giving way at an intersection with traffic lights not operating or only partly operating
(1) This rule applies to a driver at an intersection if traffic lights at the intersection are not operating, or the traffic lights are showing only a flashing yellow traffic light.
Note. Intersection and yellow traffic light are defined in the Dictionary.
(2) If there is a traffic light-stop sign at the intersection, the driver must comply with rule 67 as if the sign were a stop sign at an intersection without traffic lights.
Maximum penalty: 20 penalty units.
Note 1. Rule 322 (3) and (4) deal with the meaning of a traffic sign at an intersection.
Note 2. Rule 67 deals with stopping and giving way at a stop sign or stop line at an intersection without traffic lights.
Note 3. There is no requirement under Division 1 of this Part for a driver to stop for a flashing yellow traffic light or traffic lights that are not operating.
(3) If there is no traffic light-stop sign at the intersection, the driver must give way to vehicles and pedestrians at or near the intersection in accordance with rule 72 or 73 as if the intersection were an intersection without traffic lights, or a stop sign, stop line, give way sign or give way line.
Re: Traffic Lights
Posted: Mon Apr 29, 2013 8:21 pm
by mikesbytes
That's interesting, I thought they designed to the bus lane detector to only pick up large vehicles, ie Bus's to stop cars using the Bus light, but clearly they are no different.
Re: Traffic Lights
Posted: Mon Apr 29, 2013 9:49 pm
by duncanm
mikesbytes wrote:That's interesting, I thought they designed to the bus lane detector to only pick up large vehicles, ie Bus's to stop cars using the Bus light, but clearly they are no different.
me too.. which is why I was somewhat surprised... I'm very careful to stay off the loops on that intersection these days.
Re: Traffic Lights
Posted: Tue Apr 30, 2013 3:35 pm
by KonaCommuter
duncanm wrote:mikesbytes wrote:That's interesting, I thought they designed to the bus lane detector to only pick up large vehicles, ie Bus's to stop cars using the Bus light, but clearly they are no different.
me too.. which is why I was somewhat surprised... I'm very careful to stay off the loops on that intersection these days.
Don't these posts belong on the BNA Biggest Loser thread?
Re: Traffic Lights
Posted: Tue Apr 30, 2013 7:55 pm
by Mugglechops
I used to have a set of lights that didn't work on my commute. I used to push the pedestrian button then go back and wait.
Then I found another way to ride and don't have any lights at all on my commute now
Re: Traffic Lights
Posted: Thu May 02, 2013 8:35 pm
by KonaCommuter
Mugglechops wrote:
Then I found another way to ride and don't have any lights at all on my commute now
Nice work
Re: Traffic Lights
Posted: Wed May 29, 2013 8:10 pm
by hugh stone
I remember reading a post somewhere suggesting that you are more likely to trigger the induction loop at the edges - seems to work for me.
Re: Traffic Lights
Posted: Thu May 30, 2013 8:40 am
by VRE
To complicate this further, some lights can be reprogrammed to have a longer delay between the loops being triggered and the lights changing. This occurred at an intersection I use early each morning, and initially I thought the loops had just stopped detecting me, but then found out that they still detect my bike, but there's a lag of about a minute between detection and the lights changing.
Re: Traffic Lights
Posted: Thu May 30, 2013 10:46 am
by find_bruce
heuston wrote:I remember reading a post somewhere suggesting that you are more likely to trigger the induction loop at the edges - seems to work for me.
That is mostly true - for example the US Department of Transport handbook I quoted above states
[quote="
Transport Traffic Detector Handbook Ch 2]When the cycle is directly over the loop wire, coupling between the inductive loop and the cycle is maximized.[/quote]
The reason I qualified this by saying "mostly" is that separated bike paths in Sydney tend to use a
quadrupole-loop, in which case you maximise your detection by being directly over the loop wire in the centre.
Of course there are much better detector arrangements that don't matter where you position your bicycle, but it would appear that the RMS don't GAF
Re: Traffic Lights
Posted: Sun Jun 02, 2013 10:25 am
by higdawg
I went for a ride this morning and had to go through 2 sets of lights.
I pulled up at the red light and stopped right on the middle loop on the ground with my front wheel at the front of the loop.
Set off the lights immediately, they changed within a 10-15 seconds of me pulling up.
Re: Traffic Lights
Posted: Sun Jun 02, 2013 11:09 am
by wombatK
mikesbytes wrote:
Yesterday I was waiting at a light sitting in the correct position to be detected (I could see the lines in the tarmac) and it went thru 2 complete sequences without detecting me.
Find the traffic signal box at the intersection, note it's ID number, and then call the complaints line
(included on the standard sign on the box, IIRC 131 700). Report that the detector is faulty and needs adjustment.
Can usually do all this while waiting for the next failed cycle to run its course.
The detectors are supposed to pick-up bicycles (most CF ones have enough metal in the rims/spokes
to work). The sensitivity of the detectors is adjustable. And RMS (formerly RTA) signals staff should
be able to fix it. You've just got to tell them - and doing so has worked for me.
It might even work if you ring them now and tell them the crossroads or location of the lights.
Cheers