Imagine a law prohibiting gravity. Imagine a law prohibiting water to boil. Imagine the police fining every person for walking down stairs. Imagine the police fining every person for making coffee. How much money do you think the police would make doing this?

Well you do not have to imagine because that is exactly what the police are doing with respect to drivers running red lights. The reason why red-light cameras make the obscene profit they do, is because California traffic engineers apply a mathematical formula for yellow-light times which directly contradicts Newton’s laws of motion. California has been doing it for 50 years. California enforcement’s incompatibility with the laws of physics entraps drivers and guarantees a steady stream of involuntary red-light runners. Redflex, ATS, ACS and every red light camera company simply step in to exploit the error. The result is an insane amount of profit. The result is also a guaranteed steady stream of crashes and fatalities. The slogan from the old commercial is very true: “It is not nice to fool Mother Nature.”

Just like cameras do not enable drunk drivers to drive undrunk, neither do cameras enable drivers to walk on water.

Use of the formula requires two things from a driver: 1) that when a driver sees a yellow light but he is too close to stop, he must not decelerate below the speed limit before entering the intersection, and 2) that a driver knows exactly where the distance “v(t + v/2a)” is from the intersection. The algebraic expression “v(t + v/2a)” is called the critical distance.

In order for a driver to always make the correct decision between stop and go, the driver must know where this distance is to within 10 feet or about 1/6 of a second. Consider requirement one — no slowing down. Turning drivers must slow down before entering the intersection. For purposes of turning, California’s yellow light time can be as much as 4.5 seconds too short. A driver can approach the intersection just at the wrong moment when the light turns yellow and California will force this driver to run a red light. As for (2), human brains do not have built-in radars. We cannot compute the critical distance to precision. We have to judge between stop or go, a judgment we have making for decades. But our judgments are imprecise and red-light cameras require our judgments to be precise. That is impossible. All drivers run red lights by fractions of a second several times a year. Those fractions of a second make up 83 percent of a red-light camera company’s revenue.

For you scientists out there, look at the critical distance formula again. See the “2” in the denominator? See anything wrong with that? All objects in the universe must comply with the Newtonian equation of motion t = v/a.

Brian Ceccarelli lives in Apex, North Carolina.

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## Join the Conversation

1. Righteous_Nerd says:

The 2 in the denominator comes from the fact that, during the window of deceleration, your average speed is v/2.
$d = \int_{0}^{v/a} v(t) dt = \int_0^{v/a} (v – at) dt = v(v/a) – 1/2 a (v/a)^2 = v(v/(2a))$
If t is your reaction time (e.g., 1/6 th of a second), the full formula is
d = v(t – v/2a), as given.

Please remove or update this misinformative article.

2. Righteous_Nerd is not righteous. The 2 comes from the stopping distance formula v^2/2a, where v is the initial speed before decelerating. t + v/2a is the yellow light time. The yellow light time is the time it takes you to traverse the stopping distance at the initial speed; that is, the speed limit. Once you cannot stop, you must go the speed limit or faster in order to make it into the intersection before you run out of yellow.