Red-light cameras are often billed as a great way to improve traffic safety and prevent speeding. A few cities across America, however, have been caught short-timing their own yellow lights below legal levels in what may be an attempt to boost ticket revenues by giving drivers less time to come to a stop. So how many anecdotes do you need to pronounce something a trend? It's hard to say, especially when the anecdotes in question support the abolishment of something as universally hated as the red light camera.

Six possible red-light "gotcha" stories, some of which go back as far as 2005, were originally reported by theNewspaper, but were compiled into a single list of events by motorists.org. One city, Chattanooga, Tenneessee, has been forced to repay the $8,800 it collected in ticket revenue, while investigations in Lubbock and Dallas, Texas and Springfield, Missouri, have uncovered evidence of similar practices, although no charges have been filed.

In the single court case that has occurred thus far, Chattanooga's city traffic engineer John Van Winkle testified that the yellow signal light should be (and was) turned on for the 3.9 seconds necessary to meet basic safety standards. The judge in question ordered the claim verified, and discovered that the light was only set for three seconds—significantly less than the 3.9-second minimum. Van Winkle claims that the problem was caused by an accidental mixup with turn arrow timing, but there might be more behind the issue. According to confidental documents released in 2001, Lasercraft, the company behind Chattanooga's red camera lights, only installs red light cameras at high-volume intersections with an "amber phase" of less than four seconds.

None of the other cities are facing court actions, but investigative reports have turned up troublesome trends. In Dallas, yellow lights at the city's revenue generators camera-enforced intersections were timed for just 3.15 seconds, or 0.35 seconds less than the Texas Department of Transportation minimum. In this case, a third of a second may make a substantial difference in revenue—theNewspaper reports that most (80 percent) red-light tickets are issued less than one second after the light has turned to red. Ironically, Dallas is now considering scrapping its ticket revenue program after new legislation forced the city to post signs alerting drivers to the existence of the cameras as well as requiring all towns to send 50 percent of their camera-derived income to the state's coffers.

In Lubbock, city council members eventually deployed red light cameras in the summer of 2007 after completing a series of timing tests at all twelve of the intersections scheduled to receive the cameras. As of February, 2008, however, the cameras are back down. While the cameras were initially credited with reducing the total number of crashes in Lubbock by 5.5 percent, rear-end crashes at the intersections in question rose 90 percent. The cameras also failed to generate sufficient revenue while they were deployed in Lubbock, which undoubtedly contributed to the city's decision to can the program. Several months after the cameras were switched off, the question of their use and effectiveness remains a hot topic in Lubbock.�

Springfield has a similar story. There, residents voiced concerns last spring after the city announced its intention to slash yellow lights by one second at multiple intersections. Again, evidence from the investigation indicated that longer yellow lights actually reduce the number of accidents at busy intersections. The only problem is, long yellows also have a negative impact on revenue, which can make the cameras cost more than they are worth.

In all fairness, the debate does go beyond the potential of these cameras to generate revenue. Both advocates and proponents of red light monitoring systems have produced reports on how the cameras raise (or lower) the severity and rate of accidents at a given intersection. Lubbock is a good example of how camera deployment can generate data that points in both directions at the same time, further inflaming people on both sides of the issue.

Ultimately, whether you take motorist.org's list of cities who are short-timing yellow lights as indicative of a national trend depends on where you draw the line between "trend" and "anecdote collection." But with state and city budgets tightening in the current economic climate, it wouldn't be surprising if a bona fide trend eventually emerges.