CMU, Pittsburgh’s Surtrac program aims to ease traffic congestion
About four years ago, the Penn Circle area became a test bed for the sensors, antennas and wirelessly connective traffic signals in development at Steve Smith’s lab at Carnegie Mellon University.
“Each intersection watches its traffic,” said Smith, who heads the Intelligent Coordination and Logistics Laboratory, “and essentially, in real time, builds a plan to move all the vehicles it sees through the intersection in the most efficient way.”
Or from a driver’s standpoint: “You don’t stop as often,” he said.
Congestion in Pittsburgh causes drivers an average of 39 hours of delay each year, according to the Texas Transportation Institute, and the city’s largely gridless system contains a maze of narrow roads, one-way streets, no turns on red and signals that seem to lack coordination.
That congestion is a growing problem in the East End, where rapid development is transforming an area that is home to large residential neighborhoods and some of the city’s largest institutions — including the University of Pittsburgh, CMU and UPMC Presbyterian, Shadyside and Magee-Womens — and their thousands of employees.
“It’s a lot worse,” said Michael Keyes, who works at the Metro PCS cellphone store on Highland Avenue. “Around rush hour, it gets way backed up.”
Cyclist traffic has increased as well.
“Bike traffic has gone up 20-fold,” said Melvin Franklin, a Metro PCS employee.
Keyes and Franklin said they have witnessed several bike accidents. Franklin noted that city officials have been slow to fix potholes and deteriorating road shoulders.
More adaptive traffic signals are coming to East End neighborhoods this year as CMU and the city of Pittsburgh develop the Scalable Urban Traffic Control program, or Surtrac. Aiming to ease congestion, the signals change their patterns based on traffic instead of preprogrammed cycles.
The signals piloted in 2012 at 12 high-volume intersections in East Liberty. Then nine on Penn Avenue by Bakery Square. A batch was installed from Fifth Avenue to Braddock, with plans for installation at 23 intersections on Baum Boulevard and Centre Avenue in Oakland. By midsummer, 49 intersections will host the adaptive technology, out of about 600 intersections with traffic signals citywide.
Amanda Purcell, a municipal traffic engineer with the city, said the technology must be programmed with some cycles. Purcell said when the system was installed near Bakery Square, the city received complaints from pedestrians that the timing between the walk lights and signals caused confusion. The timing had to be adjusted.
“At the city, we have to be careful about not putting something in that’s not thoroughly tested,” Purcell said. “We have to make sure everything we put on the street is going to work all the time.”
CMU’s studies on the East Liberty intersections show vehicles spend 40 percent less time idling and reduce emissions by 21 percent.
Other partners in the installation include the Southwestern Pennsylvania Commission Regional Traffic Signal Program and CMU’s Traffic 21.
Rafiq Brookins, who manages Jamil’s Products for the Mind, Body, Spirit on Penn Avenue, said he has noticed not so much a spike in car traffic through East Liberty, but a bump in foot traffic.
Stan Caldwell, executive director at Traffic 21, said research continues about how to get signals to respond to pedestrians and bicycles. In the meantime, the technology can spare municipalities the work of re-timing signals based on growth or development.
“Applying the technology is no different than in the past applying concrete,” Caldwell said. “You should still be applying it where there’s a need.”
According to the city, Surtrac received pilot funding of about $1.3 million from UPMC, Heinz Endowments, the Hillman Foundation, the R.K. Mellon Foundation, and about $500,000 in local, state and federal government grants.
The Pennsylvania Department of Transportation has plans to implement adaptive technology to signals statewide, which are all operated by municipalities. A transportation funding plan passed in 2013 authorized up to $25 million in grants for traffic signals on state-owned roads in the 2015-16 year, and up to $40 million starting in 2016-17.
PennDOT has paired with the Southwestern Pennsylvania Commission for a federally funded program to re-time lights and incorporated adaptive signal technology on Route 19 through Pine and McCandless during a recent reconstruction project.
Todd Kravits, district traffic engineer for PennDOT, said it typically costs about $175,000 to $200,000 to outfit an intersection with new signals. Adding adaptive technology adds about $40,000, he said.
Melissa Daniels is a staff writer for Trib Total Media. She can be reached at 412-380-8511 or firstname.lastname@example.org.