The Utah Department of Transportation expects to get more criticism than compliments.

But the installation of new traffic signals the past four years has proved to be the exception.Since the Utah Department of Transportation started using the first protective/permissive left-turn signal in 1986, motorists have been freed from traffic backups the older signals caused.

And some have even called UDOT to express their pleasure with the lights.

"It is nice to receive compliments for something we have done," said Dave Miles, UDOT traffic and safety engineer.

He said there have been a few complaints, mainly from drivers who still get confused by the continuous left turn.

The signals have a protective phase, when the 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 signals caused at busy intersections.

It took UDOT a while to get funding for the signals that had actually been around for about 20 years. The perception for a long time here and in many parts of the country, Miles said, was that the signals would create confusion and cause accidents.

But for the most part, the opposite has been true in Utah.

"I think they have improved traffic flow. I am very happy with them," said Salt Lake City transportation engineer Tim Harpst.

But one thing keeps UDOT from installing the signals at every busy intersection in the state: money.

Miles said installation of the signals costs from $15,000 to $80,000, depending on how extensive the intersection upgrade is. This fiscal year, UDOT has $150,000 to spend on protective/permissive signal upgrades.


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24 intersections to get new signals

Some of the 24 intersections where UDOT will install protective/permissive traffic signals in the next two years:

Salt Lake City

State Street at 3900 South (E-W), 6100 South (N-S) and 9000 South (E-W)

700 East at 400 South (E-W), 800 south (N-S and E-W) and 9000 South (E-W)

3300 South at 300 West (N-S) and 1300 (E-W)

3500 South at 3200 West (E-W) and 3600 West (N-S and E-W)

5400 South at 700 West (N-S and E-W), 3200 West (N-S and E-W) and 4015 West (E-W)


U.S. 189 and 2230 North


Main Street and 2600 South (E-W)