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Portland, Maine Ready to Flip Switch on Smart Traffic Signals

City officials here will flip the switch next week on an innovative system designed to ease traffic flows through the most congested intersection in the Pine Tree State.

They expect the Morrill’s Corner project to cut wait times along the important commuter roads feeding through the intersection by 20 to 30 percent. Bottlenecks there have frustrated drivers for years. It’s a problem every weekday, since the city’s core population of 67,000 swells to 200,000 as suburban workers drive to their jobs.

The project is only one of several traffic-related initiatives the city has ambitions to complete in the next few years, as it attempts to keep the high quality of life that has been a magnet for companies and workers in recent times. To knuckle under to a life of gridlock would be to jeopardize the “secret sauce” that makes Portland such a desirable location, said City Manager Jon Jennings in a recent interview.

A true technophile, Jennings believes that a wide variety of “smart” systems will improve life in the city. Portland will soon finish replacing all of its street lights with a state-of-the-art LED system that is electronically linked and compliant with dark-sky standards. It has just gone live with public wi-fi systems in two much-used parks. And the city will soon launch a project to address conflicts between pedestrians and vehicles along the busy waterfront. Portland is an ideal testbed for cutting-edge solutions to problems found in many larger cities, Jennings said.

The Traffic Challenge

Portland’s traffic congestion was on display on a recent morning during a drive from Falmouth on Interstate 295. One key southbound exit turned out to be in gridlock, held up by poorly coordinated lights within one block of each other, one controlling us and the other controlling northbound drivers who were also exiting 295 and competing to get onto Franklin Street to go downtown.

At City Hall, Jennings and his technology adviser Troy Moon said the Franklin Street bottleneck is on the agenda after the Morrill’s Corner and associated traffic problems are addressed.

Moon took this Route Fifty correspondent out to Morrill’s Corner. As if to underline the point that traffic is a big problem in Portland, we got stuck at Woodford Corner, just a mile or so from our destination. What seemed like an easy right turn was prohibited by traffic signals feeding other roads through the intersection, with the delay exacerbated by a passing train that blocked one of the thoroughfares.

Finally breaking free, we drove through Morrill’s Corner from every direction, along the major commuter routes that feed the city’s workers to their jobs.

Moon explained that the new system uses radar sensors measuring oncoming traffic along five different roads that feed into the bottleneck. They are in turn connected to new smart signals that adjust their timing to accommodate the highest possible traffic flow. The relatively small number of pedestrians crossing Morrill’s Corner intersections can punch a button to allow them to cross.

The system was developed at Pittsburgh’s Carnegie Mellon University. Researchers there recently spun it out as a new company, Rapid Flow Technologies LLC, with the goal of commercializing the Surtrac adaptive signal control technology developed in the university’s Robotics Institute.

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