SURTRAC  is designed to discover the dominant flow of vehicles through an intersection and automatically adjust the signaling. It is designed to operate within urban grids, where the volume and direction of traffic can change throughout the day.

At the East Liberty intersections, cameras take continuous shots of the traffic, which allows SURTRAC to create a schedule for moving vehicles through the intersections in the most efficient way possible. Each intersection also communicates via a fiber optic cable (or, in the case of one East Liberty intersection, a wireless signal) to its downstream neighbors as to what the projected outflow from its signal will be. The neighboring signals do the same thing, and together they create a communications network that’s akin to having the watchful eyes of traffic police at every intersection.

More impressive, though, are the net results. At the East Liberty intersections, the research team found that the wait time for people driving through the grid was reduced by 40 percent. Travel time was reduced by 26 percent, and projected vehicle emission by 21 percent. The researchers obtained the results by completing “before” and “after” drives along 12 pre-determined routes through the nine intersections. They did the drives during four set times throughout the day; GPS tracers on their cell phones allowed them to gather the data necessary to calculate the differences.

“When I saw the results, I was really shocked that they were as good as they were,” says Allen Biehler, executive director of CMU’s University Transportation Center and former secretary of the Pennsylvania Department of Transportation. Although Biehler says that more “robust testing needs to be done” by expanding the pilot grid in an effort to obtain more data, he expects other cities throughout the United States will be interested in SURTRAC. In November, during the annual meeting of the American Association of State Highway Transportation Officials, Florida Transportation Secretary Ananth Prasad invited Biehler and Smith to discuss SURTRAC with his state’s Department of Transportation. “This (technology) will have far-reaching implications,” Biehler says.

Nate Cunningham, director of real estate for East Liberty Development Inc., sees the ease in congestion at the East Liberty intersections as a boost to the local economy. “There is no more important thing to make a community competitive than being able to move people easily from place to place,” Cunningham says. “I can see how (the ease in traffic flow) will have an impact on real estate in East Liberty.”

Another advantage, says Cunningham, is that municipalities can implement the technology incrementally. Once an intersection has been upgraded to include detection equipment, a SURTRAC system can be installed to monitor traffic in real time. “What’s exciting is that this is so powerful and so cheap. Cities can bite off little chunks at a time, as funds become available.”

Amanda Purcell, municipal traffic engineer for the City of Pittsburgh, says that the pilot project in East Liberty “is working fine” and will help “establish a baseline for how the signals operate.”

She says talks are under way to expand the project, which has already received approval to install SURTRAC-supported signals eastward from East Liberty along Penn Avenue to Fifth Avenue. Nine more intersections will be added to the grid during spring of 2013 …

A computer-enhanced corridor into Pittsburgh may not match the Roman accomplishment of “all roads leading to Rome,” but a faster way into town should please many drivers.


The Link Magazine (CS.CMU) Spring issue: All in good time