kds@intelca.UUCP (Ken Shoemaker) (06/07/85)
I'm kinda new to this, so please bear with me...when riding in this area
it sometimes becomes useful to turn left (suprised?). However, there are
a couple of problems with this:
1) most left turns around here have sensors in the street, so they don't
change unless something large and metalic is sitting on them.
(although I have been able to get some of these to change!)
2) there are some places where there is a left turn lane and a left/straight
lane, which lane to use?
In either of these two cases, you usually end up stuck inbetween two lanes
of whatever, a situation where I personally don't feel too comfortable...
I suppose one option would be just to get off, and walk the bike through
the crosswalk, which I also do, even though I am a vehicle. Anyway, what
is the general consensus as to how to approach this problem?
--
It looks so easy, but looks sometimes deceive...
Ken Shoemaker, 386 Design Team, Intel, Santa Clara, Ca.
{pur-ee,hplabs,amd,scgvaxd,dual,qantel}!intelca!kds
---the above views are personal. They may not represent those of Intel.bill@utastro.UUCP (William H. Jefferys) (06/08/85)
> > 1) most left turns around here have sensors in the street, so they don't > change unless something large and metalic is sitting on them. > (although I have been able to get some of these to change!) > A tough one. I someties can get them to change by sitting right on top of the wire, but it's iffy. The best solution is to talk to the city traffic engineer and get them to install these sensors as "figure eight" loops rather than simple loops. This makes them more sensitive to objects on top of them and at the same time less sensitive to cars in the next lane. See John Forester, *Bicycle Transportation*, pp. 269-274 (MIT Press 1983) for details. > 2) there are some places where there is a left turn lane and a left/straight > lane, which lane to use? > Use the rightmost lane if there are two designated left turn lanes. Never make a left turn from the right turn only lane or the straight-through only lane. > In either of these two cases, you usually end up stuck inbetween two lanes > of whatever, a situation where I personally don't feel too comfortable... Always take the *middle* of the lane at an intersection. Don't allow yourself to be sandwiched between two cars (or between a car and the curb). -- "Men never do evil so cheerfully and so completely as when they do so from religious conviction." -- Blaise Pascal Bill Jefferys 8-% Astronomy Dept, University of Texas, Austin TX 78712 (USnail) {allegra,ihnp4}!{ut-sally,noao}!utastro!bill (uucp) bill%utastro.UTEXAS@ut-sally.ARPA (ARPANET)
kehoe@reed.UUCP (Dave Kehoe) (06/09/85)
In article <605@intelca.UUCP> kds@intelca.UUCP (Ken Shoemaker) writes: >I'm kinda new to this, so please bear with me...when riding in this area >it sometimes becomes useful to turn left (suprised?). However, there are >a couple of problems with this: > >1) most left turns around here have sensors in the street, so they don't > change unless something large and metalic is sitting on them. Most intersections with traffic sensors also have pedestrian "Push Button For Walk Signal" things. If I'm going straight, I often get off and push the button. That doesn't help if you're turning left, of course. The "when in doubt, become a pedestrian" is good advice. In some states it's legal for a bicycle to make a left turn from the right lane by 1) crossing the street (like you're going straight) then 2) getting into the right lane of the cross street (and waiting for the light). Even if it's not lawful in California it probably isn't unlawful, and it's one of the safest ways to make a left turn.
richl@daemon.UUCP (Rick Lindsley) (06/10/85)
The first move I make is to take the full lane and signal, so that
nobody is confused about what I am trying to do.
The second move is to try not to be the first guy in line if I can help
it, because of those sensors. If a car pulls up behind me while I'm
waiting I let him pull ahead of me and I take the position behind him.
(Some drivers will look at you strangely but none have ever complained!)
If I have sat through a full cycle of lights and not gotten the green
(or the cycle does not seem to be changing) and the intersection is not
a complicated one, then I treat the intersection as I would one with a
broken signal -- I turn left when it is safe to turn left. I have been
told by a police officer that this is perfectly acceptable as long as I
do it safely. (Of course this may have been acceptable to *him*, but
perhaps the next officer won't feel that way; I don't know. But it does
have the benefit of making sense.)
If the intersection is a complicated one (more than 4 streets or a
peculiar cycle or anything that makes me nervous like a high number of
trucks) then I go the pedestrian route.
Rick Lindsley
...{decvax,ihnp4,allegra}!tektronix!daemon!richlken@turtlevax.UUCP (Ken Turkowski) (06/11/85)
In article <605@intelca.UUCP> kds@intelca.UUCP (Ken Shoemaker) writes: >I'm kinda new to this, so please bear with me...when riding in this area >it sometimes becomes useful to turn left (suprised?). However, there are >a couple of problems with this: > >1) most left turns around here have sensors in the street, so they don't > change unless something large and metalic is sitting on them. > (although I have been able to get some of these to change!) > >2) there are some places where there is a left turn lane and a left/straight > lane, which lane to use? > >In either of these two cases, you usually end up stuck inbetween two lanes >of whatever, a situation where I personally don't feel too comfortable... >I suppose one option would be just to get off, and walk the bike through >the crosswalk, which I also do, even though I am a vehicle. Anyway, what >is the general consensus as to how to approach this problem? (1) If there are no cars turning left with you, wait until there is a break in traffic, and go. You would do whatever you would normally do when the stoplight is broken. (2) Eventually you want to end up on the right side, so the left/straight would be better, although both are legal. Another way to make a left turn is to stay in the right lane, cross one street, stop and turn left, then proceed across the other street. It's longer, but safer. -- Ken Turkowski @ CADLINC, Menlo Park, CA UUCP: {amd,decwrl,hplabs,nsc,seismo,spar}!turtlevax!ken ARPA: turtlevax!ken@DECWRL.ARPA
rick@ucla-cs.UUCP (06/11/85)
>I'm kinda new to this, so please bear with me...when riding in this area >it sometimes becomes useful to turn left (suprised?). > ... > ... Anyway, what >is the general consensus as to how to approach this problem? >-- >Ken Shoemaker, 386 Design Team, Intel, Santa Clara, Ca. I do one of two things depending on the amount of traffic in the area. If traffic is heavy I ride through the intersection on the right, and stop on the other side. I then pick up the bike and turn it 90 degrees so that I am facing in the direction I want to go (the left turn). If traffic is *really* light then I simply zip over to the left run lane (if there is one, if not then I do the previous) and make a "regular" left turn. You have to be careful with this because you are virtually invisible to car drivers. -- Rick Gillespie ARPANET: rick@ucla-locus.ARPA or (soon) rick@LOCUS.UCLA.EDU UUCP: ...!{cepu|ihnp4|sdcrdcf|ucbvax}!ucla-cs!rick SPUDNET: ...eye%rick@russet.spud
nessus@nsc.UUCP (Kchula-Rrit) (06/12/85)
>In article <605@intelca.UUCP> kds@intelca.UUCP (Ken Shoemaker) writes: >>I'm kinda new to this, so please bear with me...when riding in this area >>it sometimes becomes useful to turn left (suprised?). However, there are >>a couple of problems with this: >> >>1) most left turns around here have sensors in the street, so they don't >> change unless something large and metalic is sitting on them. > > ... > The "when in doubt, become a > pedestrian" is good advice. In some states it's legal for a > bicycle to make a left turn from the right lane by 1) crossing > the street (like you're going straight) then 2) getting into > the right lane of the cross street (and waiting for the light). > ... I have ridden in Chicago(!) and Phoenix, two places which I do not consider bicycle-friendly, using the above-mentioned method for approx 3 years without any problems. Well, if the cross street was not busy... Kchula-Rrit
fred@varian.UUCP (Fred Klink) (06/14/85)
> >1) most left turns around here have sensors in the street, so they don't > > change unless something large and metalic is sitting on them. > Try touching your toe clip (assuming you use them) of the pedal you've removed your foot from to the sensor. Most will reach if you lean the bike a bit or use 175mm cranks like me. Also, angle the bike across one corner of the sensor. That seems to do a better job of interfering with the EM field. I live in California also, and this has about an 80% success rate. It angers me however that the state can declare a bicycle a vehicle and then interfere with its safe and efficient operation with these ridiculous sensors. My motorcyclist friends have the same problem, incidentally. Does anyone know if these sensors have adjustable sensitivity? They are based on a metal object interfering with a magnetic field, so I should think so.
wagner@uw-june (Dave Wagner) (06/25/85)
> >1) most left turns around here have sensors in the street, so they don't > > change unless something large and metalic is sitting on them. > > It angers me however that the state can declare a bicycle a vehicle > and then interfere with its safe and efficient operation with these > ridiculous sensors. My motorcyclist friends have the same problem, > incidentally. Does anyone know if these sensors have adjustable > sensitivity? They are based on a metal object interfering with a > magnetic field, so I should think so. > In fact, these sensors are adjustable, but if the sensitivity is made too high, a really massive piece of metal (like a truck) can activate the one in the adjacent lane. This can cause problems like a left-turn signal going on when no one is waiting to make a left turn! So you see, it's not quite as simple as it seems at first. Dave Wagner University of Washington Comp Sci Department wagner@washington.arpa {ihnp4,decvax,ucbvax}!uw-beaver!uw-june!wagner "The surest thing there is is we are riders, And though none too successful at it, guiders, Through everything presented, land and tide And now the very air, of what we ride." - Frost
fred@varian.UUCP (Fred Klink) (06/27/85)
> In fact, these sensors are adjustable, but if the sensitivity is made > too high, a really massive piece of metal (like a truck) > can activate the one in the adjacent lane. This can cause problems > like a left-turn signal going on when no one is waiting to make a left > turn! So you see, it's not quite as simple as it seems at first. > Obviously, any device of this type can be misadjusted. My point is that if the device cannot be adjusted to accomadate the opera- tion of all vehicles-- trucks, cars, motorcycles and bicycles-- that legally use the road then the device is inadequate and a more reasonable system should be adopted. Also, I can't quite believe that the sensitivity required to sense a bicycle directly over the loop is even close to that required to sense a truck in the adjacent lane. Even if it is, to occasionally set off a left turn arrow when no one is there seems more desirable than not setting it off at all for motorcycles and bicycles. Fred Klink Varian Walnut Creek, CA
bill@utastro.UUCP (William H. Jefferys) (06/28/85)
> > > >1) most left turns around here have sensors in the street, so they don't > > > change unless something large and metalic is sitting on them. > > > > It angers me however that the state can declare a bicycle a vehicle > > and then interfere with its safe and efficient operation with these > > ridiculous sensors. My motorcyclist friends have the same problem, > > incidentally. Does anyone know if these sensors have adjustable > > sensitivity? They are based on a metal object interfering with a > > magnetic field, so I should think so. > > > In fact, these sensors are adjustable, but if the sensitivity is made > too high, a really massive piece of metal (like a truck) > can activate the one in the adjacent lane. This can cause problems > like a left-turn signal going on when no one is waiting to make a left > turn! So you see, it's not quite as simple as it seems at first. > Actually, there is a way around this, but it has to be done when the sensor loop is *installed*. (Described in John Forester's *Cycling Traffic Engineering*): If the loop is installed as a figure 8 instead of (as is normal) a plain loop, it will simultaneously become more sensitive to low-mass objects such as bicycles over it, and less sensitive to large objects, such as trucks, in the adjacent lane. Unfortunately, very few of the people responsible for installing these things are aware of this. It is really up to bicyclists to organize and make waves at city hall! -- "Men never do evil so cheerfully and so completely as when they do so from religious conviction." -- Blaise Pascal Bill Jefferys 8-% Astronomy Dept, University of Texas, Austin TX 78712 (USnail) {allegra,ihnp4}!{ut-sally,noao}!utastro!bill (uucp) bill%utastro.UTEXAS@ut-sally.ARPA (ARPANET)
powers@noscvax.UUCP (William J. Powers) (07/04/85)
> > In fact, these sensors are adjustable, but if the sensitivity is made > > too high, a really massive piece of metal (like a truck) > > can activate the one in the adjacent lane. This can cause problems > > like a left-turn signal going on when no one is waiting to make a left > > turn! So you see, it's not quite as simple as it seems at first. > > > Obviously, any device of this type can be misadjusted. My point > is that if the device cannot be adjusted to accomadate the opera- > tion of all vehicles-- trucks, cars, motorcycles and bicycles-- > that legally use the road then the device is inadequate and a > more reasonable system should be adopted. Also, I can't quite > believe that the sensitivity required to sense a bicycle directly > over the loop is even close to that required to sense a truck in > the adjacent lane. Even if it is, to occasionally set off a left > turn arrow when no one is there seems more desirable than not > setting it off at all for motorcycles and bicycles. > I know that in Los Angeles they have evidently solved this problem. I don't know how. Maybe some of you LAans know or can find out. Here in San Diego we have initiated a study to solve this problem. Another suggestion that might work is to add an inductor or some such resonant circuit to a bicycle that would increase its sensitivity. I do not, however, have sufficient information on the workings of these loop detectors to attempt to design such a system. If something as simple as this could be made to work the bicycling community would be greatly indebted ( not to mention the profits that might be involved ). Bill Powers
johnston@uiucdcsb.Uiuc.ARPA (07/07/85)
While you're at it, how 'bout designing the "resonant circuit" to be
"directional". That we I could trigger the left turn arrow from about
half a block away so that it would be green by the time I got there!
:->
- Gary Johnston
Department of Computer Science
University of Illinois at Urbana-Champaign
USENET: ...!{pur_ee,ihnp4,convex}!uiucdcs!johnston
CSNET: johnston%uiuc@csnet-relay.arpa
ARPA: johnston@uiuc.arpafred@varian.UUCP (Fred Klink) (07/08/85)
> Another suggestion that might work is to add an inductor or some such > resonant circuit to a bicycle that would increase its sensitivity. > I do not, however, have sufficient information on the workings of > these loop detectors to attempt to design such a system. If something > as simple as this could be made to work the bicycling community would > be greatly indebted ( not to mention the profits that might be > involved ). > Bill Powers How about a very thin aluminum strip attached to the heel of your cycling shoes? Touch it to the coil in the pavement to set off the light. Same idea as touching a toeclip to the coil. Could probably sell it for a buck per shoe.
seifert@hammer.UUCP (Snoopy) (07/10/85)
In article <16200114@uiucdcsb> johnston@uiucdcsb.Uiuc.ARPA writes: > >While you're at it, how 'bout designing the "resonant circuit" to be >"directional". That we I could trigger the left turn arrow from about >half a block away so that it would be green by the time I got there! A lot of the lights in the Portland area are like this. There's an extra sensor in the street, say 100 feet back from the intersection. If traffic is light, the light will change in time for you. What's really stupid is that the left turn lanes have a red light except for when the left-turn-only light is on. Sit and wait! Snoopy tektronix!hammer!seifert
maciag@spar.UUCP (Chris Maciag) (07/23/85)
I have found that the closest to a sure fire method is to take one foot out of the toeclipe and lean the bike over, so that the top tube is as close to the ground as possible. Most of the time you can see lines in the road where the loop is located. I always hated doing this, because I can balence on my bike (both feet in pedals with toeclips, bike stationary) for at least 15 minutes. I attatched a small piece of metal to my pump. Rather than ask city officials to dig up old loops and put in ``figure-8'' loops (expensive with patching and all), you have a better chance of getting the city to paint a square around the loop. Then you at least know where abouts to lie your top tube or drop all your change, tools and other metal items. BTW: If you want to learn how to balence, I suggest you set up a bike as a fixed gear (track style). Balencing on it is much easier. Once you learn it, you will easily be able to balence a road bike for almost any traffic light. -Chris
lsr@apple.UUCP (Larry Rosenstein) (07/24/85)
I recall reading in Bicycling a long time ago that the way to trip
these traffic lights is to ride over the edge of the loop. (This
does assume that you can see the loop, which is another reason to get
cities to paint squares around the loop.) I have had good success
using this technique, even with non-figure-8 loops.
Larry
--
Larry Rosenstein
Apple Computer
UUCP: {nsc, dual, voder, ios, mtxinu}!apple!lsr
CSNET: lsr@Apple.CSNETfred@varian.UUCP (Fred Klink) (07/26/85)
> I have found that the closest to a sure fire method is to take one foot > out of the toeclipe and lean the bike over, so that the top tube is as > close to the ground as possible. Most of the time you can see lines in > the road where the loop is located. I always hated doing this, I can imagine. You really mean "top tube"? Getting the top tube as "close to the ground as possible" means laying the bike down on the road, or maybe turning it upside down. Am I missing something?
fred@gymble.UUCP (Fred Blonder) (08/02/85)
From: fred@varian.UUCP (Fred Klink)
I have found that the closest to a sure fire method is
to . . . lean the bike over, so that the top tube is
as close to the ground as possible. . . .
I can imagine. You really mean "top tube"? Getting the top
tube as "close to the ground as possible" means laying the bike
down on the road, or maybe turning it upside down. Am I
missing something?
Aparrently you're not missing anything. I tried this a couple of days
ago and was surprised when it worked. I tilted my bike over 'till the
top tube was about 6 inches above the pavement and parallel with the
edge of the loop. I found it a real bother.
--
All characters mentioned herein are fictitious. Any similarity to
actual characters, ASCII or EBCDIC is purely coincidental.
Fred Blonder (301) 454-7690
Fred@Maryland.{ARPA,CSNet}
harpo!seismo!umcp-cs!fred