Few drivers have mastered the trick of hitting consecutive green lights as Tom Stetich has.
As Salt Lake City's traffic systems analyst, he knows just the right speed to travel and hardly ever has to stop.But even Stetich can't manage the signal at 3300 South and Highland Drive. He grumbles like other motorists over the interminable and seemingly unavoidable wait at that intersection.
"It has to be the most horrible signal in the valley," he says.
It's also a good example of a problem traffic engineers on the city, county and state level hope to solve: traffic signals out of sync on roads ruled by the three levels of government.
Highland Drive begins in Salt Lake City where Stetich controls the traffic signals. But after the intersection with 1300 East, Salt Lake County operates the next signal, which apparently isn't coordinated with the dreaded state/
county-controlled traffic light at 3300 South.
In the past year, Stetich and engineers from the county, state and Wasatch Front Regional Council formed a committee to find a way to better coordinate signals in the valley. In its first nine months, the committee has come up with a list of roads that handle a lot of traffic and need signal coordination (see accompanying box).
Once the signals on major arterials are synchronized, the committee will tackle lesser-used streets. Some adjustments could take place this year, but engineers said it will be an ongoing process to accommodate changing traffic patterns.
Most of the problems coordinating traffic signals valleywide stem from a lack of personnel. Each agency in effect has only one person to handle traffic lights.
"We have the capability of running a (coordinated) system," said traffic engineer Robert Gibby, with the Utah Department of Transportation. But he said the state has far more equipment than it has personnel needed to come up with the timing patterns.
That problem will be partially solved by a recent appropriation funding three more positions for UDOT. Lawmakers also created a committee to advise UDOT on coordination of traffic signals.
The additional manpower will be used primarily to regularly observe how signal timing affects traffic flow, Gibby said. Those surveys, along with an inventory of what equipment the city, county and state have to work with, will help system managers identify problems and work together to solve them.
The process will never end, said county engineer Bill Porter, but the creation of the multiagency committee provides the framework to react to changing traffic patterns.
The benefits of coordinated traffic signals are significant.
Porter said a stop light can reduce a road's capacity by half. But that impact can be reduced without the expense of widening a road by programming the signal's timing to accommodate varying traffic demands throughout the day.
Smooth flowing traffic also conserves energy and improves the environment. The fewer stops a vehicle makes, the less fuel it consumes and the less pollution its idling engine spews into the air.
"It's very cost effective," Gibby said.
But he doubts many motorists will notice traffic signals synchronized valleywide. "Nobody notices the green lights," Gibby said, "only the red ones."
City, county and state engineers plant to synchronize traffic signals and improve traffic flow at the following priority locations:
- 700 East, 700/900 East, 2000 East and Van Winkle Expressway.
- 3300/3500 South
- 4500/4700 South
- State Street
- 3900/4100 South
- 5600 West
- 9000 South
- Redwood Road
- Highland Drive, 1300 East and 2300 East
- 5400 South
- 7200 South
- 7800 South
- 10600 South
Upon completion, West Valley Highway will be given top priority