There are only two things that you need ask yourself the next time you have to choose between running a yellow light or stopping at the intersection. 1. Will I spill my drink if I try to stop? 2. t + V/(2a + 64.4g)

The first is obvious. Nobody wants to dump a scalding mint mocha macchiato all over his lap. The second is more difficult to answer in the split second available to make the decision. It’s the equation that the Davidson County Public Works Department uses to calculate how long yellow lights should stay yellow before they turn red. Luckily for all of us, public works calculator jockeys have worked this equation out over 700 times, once for every intersection with a traffic signal in the county.

The equation takes into account things like the grade of the road and human reaction time, allowing drivers to safely clear the intersection before the light turns red—and avoid getting a ticket to boot.

But according to Joe Savage, there’s a much more sinister equation at work, one he suspects has more to do with dollars and cents than deceleration rates and intersection widths. In the past three months, Savage—a local entertainer who has appeared on the cover of this newspaper—has received three tickets for running red lights. He says that, given the timing of the yellow lights, there’s no way that anyone could have made it through those intersections before the signals turned red. “I thought, ‘Something is screwy here,’ ” he says. So Savage decided to investigate. He requested records of every citation written for running a red light since the year 2000. What he found was startling.

In 2000, about 27 people were ticketed for such violations on Broadway, according to documents the Metro Police Department provided to Savage. It was about the same number for 2001. Most of these violations took place on Broadway between Second Avenue and the intersection of Interstate 40, the same area where Savage was thrice written up. In 2002 and 2003, however, the number of violations associated with red light runners leapt to over 1,100 per year. Again, almost all the violations took place on Broadway between Second Avenue and I-40. In 2004, ticketing was even more prolific, with over 2,000 citations written for drivers who tried to push their luck at intersections. There was a slight decrease in 2005—about 1,500 violations were recorded last year—but in the first three months of 2006 there were about 500 violations, which puts Metro cops on track to write 2,000 tickets for red light violations in that area this year.

Running a red light will cost you about $80 in Davidson County. Do the math. Once Savage saw what all those violations were worth to the city, he became convinced that something was rotten in Denmark. So he took his stopwatch and visited some downtown intersections. He noticed that the closer he got to Second Avenue, the shorter the yellow light. At many intersections, in fact, he found that the yellow light was visible for less than three seconds—a violation of state law, which requires that “the minimum time exposure of a yellow light shall be three seconds.”

Thus armed, Savage appealed his last citation in General Sessions Judge John Brown’s courtroom. The judge, apparently unmoved by Savage’s evidence—including testimony from the cop who pulled him over admitting that he was actually three cars behind Savage and didn’t have a clear view of the stoplight—ordered him to pay the ticket. Savage recalls him saying, “It’s my experience that once a light turns yellow, it then turns red.”

True enough, your honor.

Savage, enraged that Davidson County has become what he calls a “totalitarian state,” insists that the police have shortened yellow light times so that it has become physically impossible to drive a car from one side of an intersection to the other in the span of time it takes a traffic signal to go from yellow to red. Claiming entrapment for the sake of fattening city coffers, Savage got an attorney and has appealed the decision. He now awaits a jury trial. If there’s one thing the Scene can’t stand, it’s the little guy getting squeezed with traffic signal chicanery. So this reporter trudged downtown—stopwatch in hand—and recorded the length of yellow lights at six intersections on Broadway.

If there’s one thing the Scene can’t stand, it’s the little guy getting squeezed with traffic signal chicanery. So this reporter trudged downtown—stopwatch in hand—and recorded the length of yellow lights at six intersections on Broadway. Sure enough, moving west from Second Avenue to the start of West End, the yellow light times grow longer. At a few intersections, specifically Broadway at Second, Seventh and 10th, the average length of the yellow light was short of the three seconds mandated by state law. Savage’s conspiracy theory was beginning to sound very credible. But it all comes back to that geeky equation.

Bob Weithofer, the city engineer who’s in charge of signal timing, insists that the police have absolutely nothing to do with timing yellow lights. That decision rests solely with his department, and he says that the equation is his unyielding guide in determining the timing of Davidson County’s stoplights. But what about the state law?

Weithofer pleads ignorance about any state law setting a yellow light minimum, but says that three seconds is “the minimum setting for yellow lights in Davidson County.” He also says that it’s technically impossible for many of the lights to be set for less than that. “It’s the way they’re hard wired,” he says.

He dismisses the timing of yellow lights with stop watches as “inexact” and says that while he’s not positive, chances are that the yellow lights become longer as you head west because you’re going uphill. “It’s easier to stop when you’re driving uphill,” he says.

As for the dramatic uptick in red light violations, Weithofer fingers the same culprit as Savage: the police. “We didn’t change what we were doing; the police department changed what they were doing,” he says. It’s true. Police Chief Ronal Serpas has made traffic enforcement a well publicized—and somewhat annoying—priority. One officer who asked not to be identified says that inter-departmental memos authored by the chief stress the importance of traffic stops as a means to catch bigger fish, like parole violators or people with outstanding warrants.

“There’s been a significant increase in traffic enforcement downtown, just as there has been throughout the city,” police spokesman Don Aaron says. Though he declines to describe the spots as “speed traps,” he does say that traffic cops know where the short yellow lights are. “If that enforcement has prevented just one pedestrian from being struck and killed by someone who blows a red light,” Aaron adds, “then it’s worth it.”

In the end, it seems that Savage is right. The cops are looking to bust more motorists. The bad news—for most of us anyway—is that, the three-second minimum notwithstanding, they have a green light from the law.