The Blog

The Yellow Menace

The police could make intersections safer with longer yellow lights. But the city wouldn't make any money that way. Part 2 in a series.

11:00 PM, Apr 1, 2002 • By MATT LABASH
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But by the late '90s, that standard had been steadily eroded by altogether shaving off clearance time, lowering yellow light intervals by as much as a third, which often leaves the motorist stranded in the dilemma zone. To make matters worse, the ITE, which in 1985 was still recommending yellow lights be lengthened to help clear intersections, now, with the advent of red light cameras, offers that "enforcement can be used instead."

The real-world translation here is that according to 1976 practices, an 80-foot-wide intersection with a 35 mph approach on a 2.6 percent downhill grade would warrant a five-second yellow light interval. But according to 1999 formulas, it is considered acceptable to allot the same intersection a 4 second interval. A second might not seem like much. Consider, however, that even automated-enforcement cheerleader Richard Retting of the Insurance Institute for Highway Safety concedes that yellow-light increases decrease the chance of red-light running incidents. Likewise, Retting's studies show that of drivers classified as "red light runners," 80 percent enter an intersection less than a second after a yellow signal has turned red.

The ITE recommendations, of course, weren't carved in stone at Mt. Sinai. Rather, they're published in scarcely read traffic manuals. But increasing yellow-light intervals at problem intersections is certainly easier, if not more profitable, than starting red light camera programs. Extending yellow times has proven successful, even if cities don't publicize it. In San Diego, where even the police chief was caught admitting that at many red-light-camera intersections, accidents have increased, the nation's bloodiest skirmish over red-light cameras has played itself out in court, revealing all sorts of city/contractor chicanery. There, lawyers representing motorists found the city planting a red-light camera at an intersection where no accidents had occurred for years. But that didn't stop the camera from generating 2,000 citations per month, until engineers realized the yellow light was more than a second too short. When they increased it, the number of citations dropped to fewer than 300 per month.

Local police departments that employ automated technology, of course, perpetually stress that their sole concern is reducing accidents. It's curious, then, what happens when you start checking just what steps they have taken to do so. When I asked the District of Columbia's Department of Public Works for a list of yellow-light times at camera intersections, almost all reported a 4-second interval. But ITE standards permit extending yellow lights up to 6 seconds. Keeping in mind that these are supposed to be trouble spots, I inquired about the last time these intervals had been changed. "Years and years ago, maybe never," one employee said. Likewise, though cities are typically coached by contractors to place cameras at heavy-volume intersections (generating more tickets), statistics from the same office reveal a noticeable shortage of red-light cameras at the city's most dangerous intersections. Of the top 10 high-crash intersections for the two years that preceded the District's installation of 39 cameras in 1999, the 1997 figures show four of the top 10 (including 2 of the top 3) did not warrant red-light cameras (even though one of them accounted for two of the only three reported deaths). Additionally, 7 of the top 10 high-crash intersections for 1998 didn't rate cameras--even though they were installed just a year later.

In other cities, the percentages are even worse. In Charlotte, North Carolina, WBTV found their safety conscious officials failed to install cameras at 23 of the highest-crash intersections. And in San Diego, the Red Light Camera Defense Team, a consortium of pro bono lawyers representing motorists against the city found that 12 of the 19 red-light camera intersections had three-second yellow intervals, and that Lockheed Martin IMS--our old friends from D.C.--had sought out intersections with high traffic volume, short yellow cycles, and downhill approaches--the kinds of intersections that citation-happy police officers used to call "cherry ponds" or "duck patches." What the lawyers didn't find was any evidence supporting officials' claims that their program, like D.C.'s and Charlotte's before it, was "about safety." Not a single one of the city's 19 cameras was operating at one of its highest-accident sites.

Tune in Wednesday for Part 3: The Safety Myth