Challenging The Yellow Light

I think this has been case has been brought up before and people have beaten the ticket or fine.

I agree yellow light length should be set to a given standard, but that standard is a function of the speed.

For example, if you have a light at an intersection with a 50 mph speed limit and compare to one at an intersection with a 20 mph speed limit - the yellow light length should not be identical. It should be calculated with a constant time which represents an appropriate reaction time plus enough time to safely stop from the speed limit.

Y = t + V/(2a+2Ag)
Y= Yellow clearance interval in seconds
t= reaction time (use 1 second)
V= 85%percentile approach speed in ft/sec/sec [can use speed limit]
a= deceleration rate of a vehicle(use 10 ft/sec/sec)
A= Acceleration due to gravity (32.2 ft/sec/sec)
g= percent grade in decimal form(+for upgrade,- for downgrade) this is
unknown.
*Calculate the yellow clearance interval to the nearest 0.1 second

Thats way to smart for me to follow. LOL

Rigel, did you stay at a Holiday Inn Express last night?

The cameras need to be disabled during bad weather. How can you stop in snow/rain/ice in 3.1 seconds? Deceleration rate of a vehicle varies by size and weather conditions, so all yellow lights on enforced intersections need to take the worst case scenario into account. How about legislation for a 10 second minimum in all enforced intersections?

where I have been staying this week???

Way too long!! It does need to be standardized based on the speed of the street in question though. 10 seconds would increase the total time for the whole light changing process. Maybe Riegel could calculate that for us

Using Riegels's calculations if you have an intersection with no grade and are going 55mph it will take 3.92 seconds to stop with a 1 sec reaction time. At 55mph in good weather the coefficient of kinetic friction is 0.8 and a car takes 37 feet to stop. In rain its 0.4 and takes the same car 252 feet to stop, in snow its 0.2 and takes 500+ feet to stop! Simple physics dictates that if its raining yellow lights on enforced 55mph intersections are too short.

Would you have to take width into account as well?

I guess that inability to stop due to a rain-slickened could make any ticket appeal-able. But you should probably just slow down and save a life, maybe your own.

jmeunier,

I'm not all that up on coefficient of kinetic friction but I've been researhing stopping distances of some of the newer cars in Autoweek Magazine over the past few months. From 60 mph to a full stop I'm finding most cars take from somewhere around 115 feet up to over 140 feet or more to accomplish this task. You state that a car traveling at 5 mph less (55 Mph) can stop in 37 feet. That sounds impossible. Was 37 a typo?

I just received a nice $100 surprise(not really a surprise) from this nearby town. No doubt I did it and I don't really have a valid excuse. I do remember being very frustrated that day as it seemed every light turned red just as I approached. Since then I have noticed several near rear end collisions as drivers slam on their brakes when a light turns yellow. The cameras here have only been operating a couple of months.

It is abundantly clear that:

shorter yellow lights = more red light violations = more municipal revenue from fines (despite the safety risks).

The source of the formula is from the Institute of Travel Engineers. Obviously, actually doing so algebra is too challenging for Government employees, so they just randomly set the length of the yellow.

And, if they can add a red camera and generate toll fees - so much the better.

The epidemic of red light cameras is here to stay because it is all about money - not traffic safety.

I was thinking in metric, oooops...

Of course the new VA traffic laws are more unjust then a 1 sec yellow light @ 55mph. If your 20 over the limit and a non-resident speeding through VA you get a $200 ticket, if you are a VA resident you get a $1200 ticket.

That's the first time I heard that tickets are also discriminating between resident and non-resident.

If you travel through Alabama you don't have to worry about traffic cameras.

I've gotten a lot of out of state tickets in CT and I always heard they charged more for out of staters, not less. It's odd that VA is opposite.

Apparently you are supposed to slow down to ~25mph in a 55mph zone if it’s raining due to the fact that the red-light camera system neglects to take inclement weather into account. Personally I would rather get a ticket than die in an attempt to go 25 in a 55mph zone during rush hour in northern VA (rain doesn’t slow anyone down around here)

Letter is posted in a link:

http://filer.case.edu/jkm26/Kaine%20Traffic%20Reply_Page_1.j...

amen to that!!!! I would run a red light first instead of slamming on brakes, loosing control and perhaps getting rear ended.

They said law and policy experts from the administration, the General Assembly and even the Supreme Court will spend the rest of the year looking for ways to collect from nonresidents fees that run into the thousands for traffic infractions and retain the revenue for road maintenance. But right now the fees only apply to VA residents, so speeding 36mph in a 15mph zone is a $100 fine for a non-resident and $1100 fine if you live in VA!!!...the way the bill is worded it could be applied to red-light cameras as well!!!

The California vehicle code requires 3.0 seconds or longer yellow light time.

The redlight camera vendor in San Diego snuck the yellow time below that for higher revenues, got caught. They dismissed thousands of illegal tickets. The vendor? Lockheed Martin.

...because they have no stoplights!!

I agree with asianfire, I'd rather take a redlight ticket than get rear ended. The picture though could vindicate you as it would show another vehicle in close proximity. I would think the ticket would have to be thrown out if you were attempting to avoid an accident. BUT, the state could also make the argument that you potentially could cause an accident in the intersection by running the light. Intersting. I wonder if there have been any cases like this?

I think most yellow lights are already based on speed. However, the 'reaction time' constant that they use to calculate the yellow length is probably too short. However, it's likely that there is no calculation involved whatsoever and they just pick arbitrary lengths of time. THAT is what needs to change.

About three years ago the first camera went in at a busy intersection in Marietta Georgia. A study was done on the accident rate for that intersections. The study was based upon detailed data obtained by actually looking at each accident report to understand the circumstances. The finding was that the accident rate for accidents that could not have been influenced by the addition of the cameras ( such as one car being hit by another car traveling on the other street ) was about the same. However, accidents from rear end collisions did not increase after the cameras were installed initially. But once the public began to become aware after the media publicised it, the rear end collision rates increased by 50%. The study found that installing the camera participated more accidents and made that intersection one of the most dangerous intersections after the camera was installed (it already had a high accident rate, the camera just put it over the top).

The news reports about this camera cited revenue as the prime motivator of installing the camera. They highlighted how quickly the camera would "turn profitable" for the city.

I happened to notice on Plano Police web site (Plano borders Dallas and Richardson), they posted the yellow light timer they use. They based it of course on the streets speed limit and none were less than 4 secs.

Dunno about other states, but Illinois has a catch-all violation worded as "driving too fast for conditions". This would include driving at the speed limit when there is ice on the road, for example. I think the court here would say that it's OUR responsibility to take into account the road conditions and adjust our speed to fit into the 3.2 second yellow light delay.

From the research that I did, to put it plainly, there are four factors to be considered:
1 the distance of the intersection
2 the speed limit
3 the grade of the approach (up/down hill, etc)
and there is something else....but can't recall.

So...let's assume that we have a level playing field (the approach). And then let's say that the Speed limit is 40mph and the distance is 80ft. In this case, the amber should be consistant throughout the city. But this is rarely that this is the case.

Check out this from a Fox investigation on Dallas's times.
http://media.myfoxdfw.com/KDFWMISC/RedLightCams/KDFW_ANALYSI...

Yellow length = 1 second per 10 MPH.

The answers to all your questions can be found at
www.highwayrobbery.net

but that's ridiculous... your ticket will read when you slam into someone in the intersection as follows:

Failure to control vehicle
Failure to maintain proper speed or excessive speed for conditions (doesn't mean you were speeding, just that you didn't adjust your speed to current conditions).

I hear that ten times a week when people are in my 2008 F650 tow truck, they can't believe they got a ticket when they weren't even speeding. It's incredulous that they rear end someone and expect to walk away without a ticket.

Same principle, if you're in ice, anticipate the light changing on your approach and be prepared to stop no matter how slow that means you have to go.

Kerry in Dallas

IF government agencies had public safety as a prime concern, they would utilize some common sense (that ain't gonna happen)in timing the yellow lights.

Yellow light timing should ALL be set to the SAME NATIONAL standard at every intersection This standard should factor in the appropriate speed for the roadway being traveled.

If every traffic light in existance used these standards, every driver would know what to anticipate as they approached the intersection.

This would reduce the "slam on the brakes" syndrom and resulting rear end crashes. Due dilligence would still have to be exercised by all (that ain't gonna happen either) regarding roadway conditions (wet, ice).

Unfortunatley, there will always be some moron or cell phone impaired soccor mom in a 2 ton SUV who is oblivious or indifferent to anything outside a 10 foot radius of their vehicle. Sadly, it's usually someone else who gets to pay the price for their stupidity or arrogance.

Personally, I would welcome a traffic camera set to National Standards at every intersection.

This is why allowing a corporation to control and calibrate the lights and then take revenue from those lights really bothers me.

That is indeed the problem.

If a police officer cites you he gets nothing for doing it except for doing his job.

By having private companies control the signals, give out the tickets and get paid on commission is a clear conflict of interest.

FWIW that was made illegal a couple years ago in California. Now the contractors who provide and operate the redlight cameras cannot be paid except by the month.

Last year I was at a city council meeting where a company salesman was pitching the system to the city. I spoke to him after his presentation. We discussed how in other states his company shared in the revenue but no longer in California. I asked him "I have to wonder why you are here?".

I told him if I were him I would be working in other states where those contracts are much more lucrative. He just shrugged.

It's all about MONEY.A lot of cities like ours (Cailf.) is in the red "no money"
They had done some studies that if all the lights were timed the right way we would save thousand of gallons of gas,there was a figure of how many gallons but can't remember that figure,plus if they where timed right we would not be stopped at every darn red light along the way on a straight away.
So now the cities claim they don't have the money to have all the lights timed the way they all should be,but the city top end are still getting their raises,and so on.
Ron

You are only ASSuming that they make more money elsewhere.

How do the monthly fees compare to the percentage fees they get elsewhere? Are they also providing other "services" that increase the total payout to the company?

And finally, if the other places result in income that equates to 1000% profit on investment, maybe your area results in "only" 500%. Still a lucritive market.

In bad weather you should not be travelling the same speed you would in good weather. Giving you enough time to come to a proper stop.