Chaos gave birth to the traffic light and continues to perfect the device that many believe was invented in Salt Lake City.

In 1912 local traffic cop Lester Farnsworth Wire - who would have celebrated his 103rd birthday this week - dipped lamps in red and green watercolors. He placed the lamps in a wooden box and hung it on a 10-foot pole in the intersection of Main Street and 200 South.Wire first set up the light at Christmastime to handle the havoc wreaked by the mix of horses and a growing number of automobiles. People initially ignored the primitive traffic regulator, but over time it caught on.

As traffic volume grows, however, traffic signals can cause more problems than they cure. A signal can reduce a road's capacity by half - a fact that has spawned developments in how traffic lights work.

The Utah Department of Transportation will spend $3 million this year installing updated protective/permissive signals. The signals have been around locally for about five years, but UDOT is installing more this year than in the past.

The name comes from the two phases of the turn-lane signals. In the protective phase a green arrow allows only left turns while oncoming traffic is stopped. Then the arrow disappears and a passive phase starts, when cars can still turn left but must yield to oncoming traffic.

By allowing cars to continue turning left, they alleviate backups in the left-turn lanes that protective-only signals could cause at busy intersections.

In addition to new signals, the state, Salt Lake County and Salt Lake City are working together to synchronize signals along streets that pass through respective state and local jurisdictions.

A committee of engineers has spent more than a year securing funding, identifying problem areas and coordinating computers that regulate signal systems. Heavily used streets are first priority, 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 lots of sophisticated equipment and only one person to handle traffic lights.

That has been partially solved with the recent appropriation to hire three more positions with UDOT. The additional manpower will be used primarily to regularly observe how signal timing affects traffic flow, said UDOT traffic engineer Robert Gibby.

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.

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County engineer Bill Porter said a stoplight's effect on road capacity can be reduced without the expense of widening a road by programming the signal's timing to accommodate fluctuating traffic demands throughout the day.

Smooth flowing traffic also conserves energy and improves air quality. 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."

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