Careful there.

The article doesn't state that the city shortened the yellow lights. They promised to not use cameras with yellows shorter than 4.4 seconds. They then started moving the cameras around to other intersections. It is possible that these different intersections had light programs with yellows shorter than 4.4 seconds.

I also don't see any mention in the article of increased accident rates.

Not disagreeing with the rest of what you said, but I just wanted to point out that the article does state that the city moved the cameras to intersections with yellows shorter than 4.0 seconds.

That's what he said. There's a difference between shortening a time interval of a light with a camera and moving the camera to a light which already has an interval that's too short. Both are wrong and breaking a promise, but the latter can happen by just being dumb, instead of bad intentions.

I don't think "being dumb" should be rewarded, either -- especially when, if allowed to flourish, such accidental stupidity can lead to willful ignorance and worse.

In furtherance of your point, a friend of mine worked for as a civil engineer involved with traffic planning in a medium city. A relevant tidbit (which I only assume to be true as, while it is perfectly logical, is not something I've ever heard taught, so take with salt) is that the solid white lines approaching an intersection are measured, and designed to act as guide markers for yellow lights, at least as originally timed.

The way it's supposed to work, is that if you're doing the spped limit and the light turns yellow, you should not stop if you are within the solid white lines, but should stop if you are outside of them.

Again, I don't know if this is 100% true, or if it is, whether it applies to all metro areas or just in Memphis, TN.

I think thats a good rule of thumb at the very least and it works for me in California.

If you brake really hard, you're probably going to decelerate at around 7 m/s2.

25 MPH / 7 m/s2 ~= 1.6 seconds.

If you get caught running a redlight, you went through the intersection > 0.5 seconds after the light turned red, which is at least > 4 seconds after the light turned amber.

If you can't stop safely in that time, you weren't driving safely, or there were exceptional circumstances (eg. an ambulance, or a tailgating semi-trailer). The video footage of the event will exonerate you in those circumstances.

The total number of accidents increase, but the number of severe accidents decrease.

I love seeing people running red lights getting flashed. It makes my day.

If you brake really hard, you may get rear-ended -- particularly if you're driving a gigantic beast of an SUV and the car behind you is a Geo Metro. I never assume someone's doing something wrong just based on the law; I also check for other factors like who's around them, what those other people are doing, whether the street is wet or oily, et cetera.

. . . and whether the speed limit in a particular area is artificially low to increase ticketing revenue.