Beware of this sneaky trap which can trick you into an accident:

Do you know what lag-trap is? (http://geocities.com/midimagic@sbcglobal.net/lagtrpqz.htm)

The sneaky part is that each driver expects the other driver to stop.

In my opinion, the agency that set up a traffic signal to produce these indications should be liable, and several courts have agreed - when they had all the facts.

But usually the police decide that one driver is lying, and the courts usually go along with the (erroneous) police report.

Legally, the driver with the yellow or red light has the duty to yield - except that he has absolutely no way of knowing that oncoming traffic still has a green light.

A solution has been developed, but federal approval of the general application of this solution is years away. The solution can be found here:

Flashing yellow arrows (http://geocities.com/midimagic@sbcglobal.net/leadlag.htm)

neither link is valid.

If I'm reading this correctly, the person who moves into the intersection to make a left turn is in violation of Georgia law. It's unlawful to enter an intersection in Georgia without being able to drive all the way through it. It's call Obstruction of Intersection.

In fact, that was the first ticket I wrote when I was a police officer in my county.

Try the links now.

They didn't work before, because the stupid BBS software shortened the text on the screen. They worked if your browser allows you to click them, but not if you copied and pasted them.

If I'm reading this correctly, the person who moves into the intersection to make a left turn is in violation of Georgia law. It's unlawful to enter an intersection in Georgia without being able to drive all the way through it. It's call Obstruction of Intersection.

In fact, that was the first ticket I wrote when I was a police officer in my county.

That's one case, but the other is that the driver moves into the intersection when the light changes to yellow, thinking he can clear before it changes to red. But he doesn't know the oncoming cars still have a green.

There is another case where I have trouble with that law. What do you do if you think you can clear the intersection before oncoming traffic gets there, and then something unexpectedly blocks your turn? This happened to me three times. And each time, the cars behind moved up. preventing me from backing up out of the intersection.

- In one case, a jogger approached a crosswalk with a DON'T WALK, then turned around and crossed the other crosswalk.

- In another case, a bicycle illegally crossed the intersection on the wrong side of the road.

- In the third case, a semi backed out of a driveway and blocked the exit of the intersection.

In each case, it left me trapped in the intersection. And doing the safer of two alternatives gets you a ticket.

The person with the yellow light shouldn't pull into the intersection at all until he can make it through.

Now if you have situations like the three that you describe, you'd have to rely on something else. Hopefully, it would be something that the officer saw, and would take into account. Maybe he'd go after the people doing illegal stuff.

I'm trying to think of the way this would work in the law where someone else does something, that puts you in a position of being in technical violation of the law. I've looked at Georgia's law for Mistake of Fact and Justification, but I'm not sure that it would cover this, since it's a strict liability offense.

I would think that common sense would come in if it made it as far as the judge. Now there could be an issue of proof. It's unlikely that you'd be able to come up with witnesses unless there was an accident that resulted.

I'm feeling a little fuzzy headed tonight. So I don't have much of an answer for your three scenarios.

I'm not so worried about the violations these situations can cause as the accidents they can cause.

The goal in traffic law is to gain compliance by citing people so that they don't get into wrecks. If we people comply with the law about not entering an intersection before you can clear it, that solves one of your scenarios.

OTOH, I don't want people cited who drive in compliance with the law, but who wind up in bad situations because someone else did something dangerous and illegal.

A lot of people don't buy it, but I am a true believer in what I do. To me it's about safety and justice.

I agree.

The real problem is that most people don't know that a traffic light can cut off one direction on a street while leaving the other direction moving with a green.

Some info:

- Some cases of this are due to bad design. In 1997, I had to show our city engineer why one intersection was producing a high number of crashes (It did the lag trap every signal cycle).

- Normally, left turn phases precede the oncoming straight-ahead phases. But if no traffic is present on the cross street of an actuated signal, it can bring up this combination by skipping unused phases.

- This phase-skipping effect causes a pattern of unusually high left turn accident frequency at night (when phase skipping is more likely). Using the standard methods, engineers usually install street lighting, instead of looking for a phasing problem.

- Often the difference in what the drivers in the crash report on the traffic signal color leads the investigating officer to believe that one driver was either lying or being inattentive. But in a lag-trap, the signal really did display different colors in opposite directions.

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This last item reminds me of the time I was called to the scene of an accident by a friend involved in the crash, who needed a ride home. She told me the light suddenly changed from green to red in front of her, with no yellow. The cop thought she momentarily fell asleep at the wheel. While I was talking to her, I was watching the traffic signal and the traffic moving around the wrecked cars. One time, I saw the signal give a yellow clearance period of only one second. I yelled to the cop about it. We watched the light, and it did not repeat this behavior. The cop thought I was making an excuse for my friend.

I had a friend who was the city's signal technician, and I asked him if this was possible. He said that other periods can be shortened or lengthened by timing plan changes for different parts of the day, but that clearance periods are supposed to be protected from that.

I saw my friend two weeks later, and he told me the signal had been malfunctioning, because the protecting information had never been entered into the signal controller's permanent EEPROM memory. It was in the RAM, and so it worked OK until a power failure occurred. Then, without the info in EEPROM to restart from, the signal controller restarted without the protection. After that, every time the master control wanted a timing change, this signal wrongly lengthened or shortened the clearance periods.