Posted on 12/09/2004 12:31:56 PM PST by weegee
Have you seen what the brits do to cameras? They drape an old tire over them and ignite it. Pretty much fries the contents of the camera. 8^>
Red light cameras generally increase the number of rear end smashups as drivers slam the brakes on to avoid a red light camera issued ticket. Instead of reducing accidents, then usually cause an increase due to this change in driver behavior.
There have also been "privacy" suits against government entities when a "robocop" photo of a speeder was mailed to the home inferred by the license plate. More than a few spouses discovered a little "cheating" was going on.
In my town, they borrowed the European 'round about' idea for traffic control, and it has worked quite nicely. I was skeptical at first but that was short lived when my 20 minute commute turned into a 5 minute one. Ditching stop lights and signs has its advantages.
Here's the reason for the all red clearance time. It stops guys like me from watching the other roads green light turn yellow, and then go when it turns red, only to be smacked by some guy running the red. It means I would have to wait until my light actually turned green or face a ticket.
It isn't a panacea, but I can see how it might help avoid a few accidents.
When traffic lights are synchronized like that, you can provide the most efficient progression for traffic on a major artery. But there is a potential safety trade-off when it comes to pedestrians. Many cities have deliberately introduced less-than-ideal signal progression in their downtown areas -- specifically to ensure that drivers don't get used to the notion that they can drive through the downtown area without ever stopping.
Actually, I don't. My comments here are more focused on the operational aspects of intersections than on the cameras themselves.
As I say, the sequential trigger of lights (timed so that the driver had to maintain a speed of 20mph when no traffic was around) keeps the speed low enough that pedestrians are not put at risk.
I really prefer a LIDAR to a RADAR. I've volunteered with local PD and actually used the LIDAR gun. It paints a 2 foot spot at 1200 feet. I can pick out a headlight or a license plate as a reflector on a specific car. The RADAR is a broad beam microwave device that covers the whole street. It is worthless with group of cars moving at mixed speeds.
One of the other article I linked mentioned being ticketed for making a right on red. How common is that?
I agree with that, however, the all-red clearance time should be in addition to the yellow time.
What has happened is that the manual now states that the all-red clearance time can be taken from the amount of time that the light would've been yellow.
So, if in the (distant) past the light would have been programmed with a 6-second yellow and NO all-red clearance time, now you can have a 4-second yellow with a 2-second all-red clearance time.
What's the excuse for unsynchronized lights when pedestrians and downtown areas are not a factor?
I'm thinking of the (Virginia) Fairfax County Parkway, which is a divided highway with a 50MPH speed limit. The traffic light synchronization on that road is atrocious.
Photographer Diane Arbus did street photography and candid portraits (so did Weegee). She wrote something like "Having your picture taken is the risk you face going out in public."
Sounds reasonable to me.
BTW, I had a problem with the "walk" lights in Dallas when I was visiting there. Here in Seattle, they flash red until the traffic with a green light gets a yellow, at which time they go solid red.
What this means is that if you are physically able to walk and run, you can pretty much always walk on a flashing red walk sign. When you see it go solid, you'd better step on it 'cuz you only got a few seconds.
Well, I was doing that in Dallas and when the walk signal went solid, I was a little over halfway across the street and THE LANES I WAS CROSSING GOT A GREEEN LIGHT.
I had an adrenelyn rush that day...
ok, good to hear,
thanks.
Also, is it common practice to shorten the yellow light time when there are no vehicles in the "dilemma zone"?
I've noticed that many traffic lights around Northern Virginia seem to have been reprogrammed recently to shorten the yellow time, but they only seem to do this when there are no cars within the dilemma zone.
There are about 4 loop detectors (referred to as "dilemma zone detectors") in all of the lanes before the traffic light spaced about 50' apart--these serve to let the light know that there is a vehicle in that range, so that it can delay a change to yellow until the are no vehicles in that zone. This is called a "gap out". Sometimes, due to heavy traffic volume, the light never gets a chance to change due to a gap out and it will instead change to yellow due to a "time out".
In those cases where it changes to yellow due to a time out (vehicles in the dilemma zone), it appears to increase the yellow time length.
Why did they make this change? Why shorten the yellow time when no cars are detected in the dilemma zone?
The conspiracy theorist in me says that's because when the red light cameras go in (after Virginia law is changed to allow them), the only loop detectors that will get any maintenance at all will be the ones for the red light camera, and the dilemma zone loop detectors...well, when they stop working, they stop working, and I guess more people will get caught for running a red.
Here they go solid several seconds before the light changes to yellow.
They also have ones with a countdown timer, which can be used by observant drivers to know about how long they've got till the light changes.
The length of the yellow should be based on sound engineering principles, but here in Houston it often is not.
As an engineer myself, I have always said that I would never be successfully ticketed in Houston for running a red light, because I would prove that the time interval of the yellow would require deceleration rates beyond the capability of even a well-maintained performance vehicle.
Were we discussing Seattle I'd agree with you. There's no excuse there for running a red. But Houston ? One second yellows on 35 mph roads are not uncommon.
"One second yellows on 35 mph roads are not uncommon."
A result of malice or incompetence?
I'd strongly lean towards incompetence. Houston police tend to be very forgiving. I passed a highway radar trap at 70 when the speed limit was 55, and no problem. He apparently was looking for the folks doing 90.
I used to carry an oxyacetylene setup in the back of my van. Yeah, I know that would upset some safety-minded folks. I never go a boot though.
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