How do properly functioning signal systems help traffic flow?  

Besides reducing congestion, effective coordination of traffic signals, saves fuel, reduces vehicle emissions, and increases safety.

UDOT has recently put more resources into developing an aggressive preventative maintenance program for signal systems. “We want to go from a reactive to a proactive program,” says Mark Taylor, UDOT Traffic Signal Operations Engineer. Ultimately, the driving public will see better traffic flow.


Sluggish traffic can be the result of saturation, or too many cars accessing the roadway. Building new roads or making existing roads wider is not always prudent or affordable.  “We just cannot build our way out of congestion,” says Taylor.

Utah’s high rate of population growth means mobility will be an ongoing challenge. Fortunately, improving signal function can help reduce delay.

Good coordination

An article on FHWA’s website reviews results from cities that have put time and resources into maintaining signal systems. A study in Virginia estimated that traffic signal improvements on a 1.5-mile of US- 17 save road users $65,000 a year in reduced delay. And a new signal system and improved signal timing in Texas produced a 13-percent reduction in travel time.

“Field studies conducted after 41 California cities re-timed 1,535 signals at a cost of $2 million in 1983 showed that vehicle stops and delays were cut by more than 14 percent, travel time was reduced by 6.5 percent, and fuel use declined by approximately 6.4 million gallons (24 million liters).”

In 2011, UDOT worked with its partners to time 164 signals and 22 corridors and realized the following benefits:

Improved Signal Timing
Travel Time Reduced – 5.5 percent
Stops Reduced – 11.4 percent
Intersection Delay Reduced – 14.7 percent
Estimated Savings to the Public in Reduced Delay – $6.2 million

Besides reducing congestion, effective coordination of traffic signals saves fuel, reduces vehicle emissions and increases safety. Because of the many benefits of well timed and well maintained signal systems, UDOT Director John Njord has charged the Traffic Operations Division with creating a world-class traffic signal system.

UDOT is committed to making even more improvements in 2012.

Leave a Comment

Your email address will not be published. Required fields are marked *