For better traffic flow, cash-strapped communities find timing is everything

Tom Fontaine
| Wednesday, Dec. 26, 2012, 8:58 p.m.

Tom Kelley says Mt. Lebanon doesn't have the room, or money, to build its way out of its traffic congestion problem.

“We can't rip out sections and sections of property for new lanes of road. We have to work smarter and make the best out of what we have,” said Kelley, Mt. Lebanon's public works director.

Mt. Lebanon is hardly alone. As state and federal transportation funding has decreased in recent years, municipalities have looked for less expensive ways to reduce congestion on its busiest roads.

Increasingly, communities are adjusting the timing of traffic signals, based on traffic volumes.

The Southwestern Pennsylvania Commission, a 10-county planning agency, recently completed the first phase of a long-term project that ultimately will adjust the timing of about a quarter of the region's 2,750 traffic signals.

The first phase began in 2008 and cost $3.75 million. It adjusted the timing of 251 traffic signals that are used by more than 440,000 vehicles a day across 40 municipalities.

By improving the flow of traffic, the SPC estimates the projects will reduce traffic delays by 21 percent, decrease fuel consumption by 16 percent and cut back on emissions by 9 percent.

SPC project manager Domenic D'Andrea said studies are under way for the second phase, expected to cost $5 million and improve about 250 intersections by early 2015, he said. Similar work is planned in the third and final phase.

The completed projects adjusted signal timing based on estimated traffic volumes at different times of the day, and synchronized the signals with others in the area.

Other projects are going a step further, using sensors and cameras to gauge current traffic conditions to adjust the timing of signals in real time.

A Carnegie Mellon University-led pilot project that targeted nine intersections in Pittsburgh's East Liberty neighborhood showed the so-called adaptive signals cut travel times through the area by 26 percent.

PennDOT used similar technology at eight intersections in a $21 million project to improve a 2.3-mile stretch of Route 19 in McCandless and Pine known as the Wexford Flats.

D'Andrea said no SPC projects, to date, have used the adaptive technology. “They are much more expensive at this point,” he said.

Duane McKee, assistant manager of Cranberry, said the SPC project has helped ease congestion in two areas of the rapidly growing Butler County township and the neighboring municipalities of Marshall, Adams and Seven Fields.

SPC said it adjusted 11 signals along Route 19 and 19 signals on Freedom Road and Route 228.

Aside from regular congestion because of Cranberry's large amount of retail development, McKee said traffic jumped after Westinghouse Electric Co. relocated its corporate headquarters to the township.

McKee said about Route 228, near I-79, carries about 5,000 more vehicles during the morning rush attributed to Westinghouse's move.

“We're in constant flux, but we're stuck in what we can afford to do. We have to make our signals work better, and this is the perfect way to do that,” McKee said.

Tom Fontaine is a staff writer for Trib Total Media. He can be reached at 412-320-7847 or

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