Signal phase adapts drivers to city lights

T.J. Gerlach

Some area traffic signals now use an “all-red” phase to adjust out-of-towners to the signals used throughout Joplin.

“An all-red phase is basically putting red lights up on every approach to an intersection in order to allow the intersection to clear of vehicles that may still be moving through or that didn’t stop at the yellow,” said Rob Smith, a civil engineer for Joplin.

The five lights in place — two on Schifferdecker, two on Maiden Lane and one at 32nd Street and McClelland Boulevard — have been in use since 2001 when the city adopted a policy to use the phase on all lights near the city limits.

Since then, no more lights have been added, but the city’s engineering department plans to add three more lights with all-red phases, one of those would be on Duquesne Road.

Sgt. Kevin Klink, who oversees the traffic desk of the Joplin Police Department, believes signals using an all-red phase are a good idea.

“That was one of the things that I was going to propose whenever I took over the traffic division,” Klink said. “The way we see it, [having all-red lights] allows those stragglers to make it through the intersection before the light [in the other direction] goes green. Apparently the driver facing a light that changes to green starts to pull out immediately. The problem is you’ve got those people that try to force a yellow light or even actually try to violate the red light.”

Klink said 2,478 accidents occurred in Joplin in 2002. Of those, 203 were the result of someone not clearing a yellow or violating a red light.

Smith said the lights in place “appear to be working fairly well,” but three years of statistics are needed to accurately show the effectiveness of the signals.

There is no difference in the equipment used. The only difference in the lighting systems is a setting in a computer. Thus, cost is not a concern for the city.

“The cost is the amount of time,” Smith said. “The phase cuts in to the time of moving vehicles.”

He also said this is the reason the lights are not used closer to the downtown area. The all-red phase expands the amount of time necessary to move traffic along.

“It would be a good idea [to put all-red signals at more intersections around the city],” Klink said, “And when you think of impeding traffic, one-and-a-half to two seconds is nothing.”