The city I live in has not caught on to the idea of left turn arrows at major intersections. This forces cars that want to turn left to run yellow/red lights. This allows for one maybe two cars, three if your lucky to turn. However that 2d & 3d car really thread the needle with oncoming traffic. I have sat at an intersection waiting to turn left 3 cycles of lights before getting impatient and “threading the needle” myself. There also seems to be a lot of car accidents caused by this practice. Is it only obvoius to me that a simple turn arrow would eliminate all this? Or do the engineers who planned this make bets on which intersection will get the most tragic news coverage on the local late night news? I was thinking this must be a money issue, but for who insurance agencies? Less accidents means less work for everybody right? Alright I’m just babbling now, and in doing so I have cut myself off!
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The traffic engineers in different communities seem to have wildly different ideas about traffic flow, which to me often don’t make a lot of sense. Arlington, Virginia is similar to what you describe–I think it should have more left- and right- turn signals. But Fairfax, Virginia goes waaay to the opposite extreme, with the most over-engineered traffic signals that I have ever suffered though. At too many Fairfax intersections, no matter which way you are approaching, you are doomed to a long wait, because the 12 different light sequences mean that in any given direction the light is red 90% of the time.
On a happy note, I’ve found the traffic light sequences at most of the intersections in the Raleigh-Durham area to be well implemented.
Restating the OP to make it a General Question: Understanding that traffic light selection and placement is a politicized process, is there an accepted engineering standard by which planners make recommendations to the politicians? What evidence should I present to my town’s traffic planner if I want her to recommend left-turn arrows to the city council?
Protected left turn lanes cost money to create and they can slow down traffic as they create an extra cycle that the lights have to go through.
In Southern California, there are quite a few of them especially near freeway onramps.
I don’t think that left turns cause as many accidents as people who run red lights, but that’s just my feeling, I have no evidence to support this whatsoever.
But if the lane in already in place, why not just add a turn light? I don’t know how much a traffic light with a turn arrow runs these days, but is there a point where the cost out-weighs the prevention?
Got to tell ya, the q confused me, but I will relate this story:
When I was getting my drivers license I of course had to take the test. The final thing I had to do was turn left from one major street to another and then drive into the DMV. The line to turn left was about half a mile long. After sitting through four cycles (this did, by the way, have a left turn arrow) I finally got to the head of the line as the light turned green for all (not just the left turn folks).
I did what the rest of the world usually does and crept out a little into the intersection to “declare my intentions,” if you will, to turn left ASAP.
After I made the turn, the DMV lady informed me I had just broken a traffic law. Apparently that’s illegal.
She passed me anyway (of course, I’m from Illinois, and given our current scandals I’m holding on to this license like GOLD) but can anyone confirm this?
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In some parts of the country, it is traditional (but not written into law) that after the light turns green the first left-turning car is expected to proceed before oncoming traffic starts to moves. If you’re not used to it, it can be very confusing and downright dangerous. So far I have experienced this phenomenon in Connecticut and around Pittsburgh. Does it occur anywhere else?
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There is a whole discipline within civil engineering dedicated to highway design. I actually studied the highway design and signalling as part of a transportation engineering course I took in college.
There sure are accepted standards for signal phazing and when it is appropriate to use a dedicated turn land or restricted turn phaze. However, there is no simple answer that can be given to broadly say that the signalization or lane design of all roads within a city should be changed.
My major project (done with two other students) for the class I took was an analysis of a single intersection of a one way street with a two way street in Philadelphia. We were required to take traffic counts at different times of the day, identifying how many vehicles made each possible movement over a period of time, as well as the breakdown of different vehicle types. If we were professionals, we would have to consider not only current conditions, but also traffic growth, among other things.
My suspicion as to why there are no turn arrows in TrayJay’s city (Phoenix, AZ, per his profile) is that the roads and traffic signals were designed when there was a much lower level of traffic in the city, but that expansion has increased demand on the road network. I’m sure that new or substantially redesigned intersections would have appropriate lanes and signals for turn movements. The city, however, is unlikely to be able to pay for a total redesign of their highway network. Rather they are likely concentrating only on intersections with particular traffic or accident problems.
You may want to contact your city’s transportation department and see if they have any input on this.
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Now wait a sec…I was driving around Phoenix today and many intersections had either designated left turn lanes or left turn arrow rotations…I guess he must live on the east side…
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Allanadale, technically it is illegal. The law is (typically) that you should not proceed into the intersection until you have a clear path to go all the way through the intersection. That little “signalling” trick is illegal because you do not have a clear path, and are relying on the fact that once the light cycles, you will be blocking traffic, and thus must move so traffic can flow.
In practice, I have never seen anyone get a ticket for it, everyone seems to do it, and as long as it’s only one (or maybe 2 cars), it is fairly practical.
But there can be hazards. For instance, I did the wait in the intersection until the light turns yellow, then pull through thing once, and almost got broadsided by an anxious driver who tried to squeeze the yellow light. I didn’t get hit, but sure got scared.
The standard thing here is on busy streets people back up behind red lights and block intersections. Because the light ahead doesn’t cycle the same, the cross traffic has nowhere to go because the putzs who couldn’t wait are in the way, so they drive into the intersection to get a chance to go. Then the light cycles the other way and traffic is blocked from two directions before the other light finally lets the cars start moving. Yes, it is a major pain, and in one case exacerbated by a spot under construction where 4 lanes narrow to two lanes. There’s a free lane that suddenly becomes a left turn only, and frequently drivers try to race around the busy lanes up the free lane, then cut over to get out of the left turn lane at the last minute. Very aggravating.
Um, I’ve never seen this as a common practice. And it is so extraordinarily dangerous, I can’t believe that it is not strictly cracked down on if it is as widespread as you claim. My guess is that you just have an inordinate amount of dickless assholes driving around your city. If whoever taught you to drive told you this is a traditional way of doing things he is either a bad day away from being a road rage murder victim, or the biggest auto-felcher on the road. I’d sideswipe you on principle.
I don’t live in a place where this is common, thank God. Nobody taught me to do it. I haven’t spent very much time in Pittsburgh so I’m not sure how common it is there. But in South-eastern Connecticut (New London, Norwich, Groton) everybody does it, or at least they did five or ten years ago.
Why is it dangerous? The driver can get out the way before the other traffic can get through the intersection, and it assures that at least one car will get through each car. Furthermore, by moving farther into the intersection, you have less distance to move, making it less likely that you’ll be hit by oncoming traffic, making it safer.
Omni, I think you misunderstood. The practice is to move straight into the center of the intersection without turning so as not to block an opposing lane.
The fact that this is illegal is a complete surprise to me. I’ve been driving for over 30 years (not that that makes me a great driver, just a statement of my experience). I’ve seen only two occasions where someone did not proceed into the intersection, and that was about three years ago.
I distinctly remember my H.S. driver’s ed instructor saying that when entering the intersection prior to a left turn, you shouldn’t turn the steering wheel so that you wouldn’t block the opposing lane. So the implication is that he, at least, thought it was legal. Again, this was over 30 years ago.
I came across a 1994 Illinois Rules of the Road, and it doesn’t say anything either way about entering the intersection on a left turn. If it is definitely illegal, it should say so in the current RotR.
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If traffic is backed up and you’re not allowed to pull into the intersection, are you just supposed to wait there for 3 hours until nobody’s coming 180 lights later? (Because, of course, it’s illegal to switch lanes that close to an intersection, so once you’re in the left turn lane, you’re stuck until you turn.)
I can’t stand the fact that half of America is breaking some driving law every moment they’re on the road. We should try to converge on a few common sense measures and eliminate all of the catch-22’s.
Regarding preceding into the intersection, then waiting for the traffic to clear before completing the turn - I was taught that this is OK as long as you are the first car in line. If the guy in front of you enters the intersection (signalling a left turn), then waits for traffic to clear, you should hang back behind the line until he is able to get out of the intersection.
bibliophage, the way I read your statement implied to me that it is common for the turning lane to proceed “before the oncoming traffic”. Ergo, accelerating and completing the turn ahead of the potentially rabbit starting oncoming traffic. This is clearly to me illegal, and quite reckless. I have seen it occasionally by the resident cocksucker on the road. Now if you intended to imply that the turning lane cars proceed forward a few yards into the intersection as the light goes green (as the oncoming traffic goes past) and potentially starting the turn if there is a substantial median, then you are correct and I agree. This is nearly the only practice in Illinois (those who stay back are accosted, this appears to be the way they are instucted in Missouri to our shegrin), and it seems to be fully legal.
A side note, Pheonix has many turning signals, or they did when I was there. One reason that is in my memory is because we made note that they have the turning arrow go green after the solid green signal. In Illinois (mostly) the green arrow goes before the solid green light. Personally Pheonix’s method is far more practical, especially if there are computer signals that can override a unneeded arrow.
Actually, it’s not very reckless if you’re making that turn with a 300-torque sports car before the dumptruck on the other side even realizes the light has turned green. Everything’s relative.
To clarify what the common practice is in Southeastern Connecticut:
In the absence of any left arrows, when the light turns green (for both directions) the first car that is turning left is expected to complete his left turn before oncoming traffic starts to move. If you don’t immediately make the turn, the driver will often try to wave you through. If you still don’t make the turn, the driver will wave again, this time using only one finger.
Let it be clear that I don’t believe this practice is legal, but I’ve never heard of anyone being ticketed for it. Let it be clear that I don’t approve of the practice. Let us hope that as left-turn arrows become more common, the practice will die out.
In St. Louis, we either have a left turn arrow, or a sign saying “Left Turn Yield on Green”. If you get caught in the intersection after the light has turned yellow, you are usually allowed to complete the turn and get out of the intersection. I never heard it was illegal to go into the intersection while waiting to make a left turn.
How about this for a confusing law? Last October, I got a traffic ticket for not stopping for a red light before going into a right-turn yield lane. Nowhere in the Rules of the Road does it say that when a right turn lane has a yield sign that you have to stop if the light is red, then yield, then make your turn, as if it were a regular right turn. As far as I know, you never have to stop for a yield sign, only slow down and look first. If anybody knows what I’m talking about, please enlighten me!
Everything’s relative.