New synchronized traffic signals that Carnegie Mellon University is developing for Pittsburgh may speed up the morning commute, but they could cut a well-paying pastime for off-duty police officers.
During construction projects Downtown, motorists can't go a block without seeing them: uniformed officers clicking traffic lights from red to green, a job usually left to a couple of circuits. With Pittsburgh's traffic-control system stuck in 20th century, officials say a simple detour can flummox traffic signals to the point of gridlock, providing steady employment for an army of officers paid extra to keep traffic moving.
But that was put in jeopardy this week, when CMU's Traffic21 Initiative proposed an alternative -- a computerized system that takes a look at traffic and coordinates lights at intersections. A pilot program in East Liberty showed that vehicle wait-time could be cut by 40 percent or more. These new lights make second-by-second calibrations to accommodate traffic flow, even in construction zones, and are set for citywide deployment within five years.
Does that mean they could soon replace their safety-vested counterparts?
"I believe so, for sure," said Stephen Smith, director of the Intelligent Coordination and Logistics Laboratory in CMU's Robotics Institute. "They do a great job, but just having the ability to let the computer crunch on different options can really give you a good result."
For years, on- and off-duty police officers have supplemented traffic signals during times of congestion. Not long ago, it was a common sight to see officers on nearly every Downtown corner during rush hours, said Pittsburgh police Cmdr. Scott Schubert, who helps coordinate traffic operations.
These days, they're mostly called in for PennDOT construction projects and stadium events. In most cases, the city pays nothing -- PennDOT or the event venue picks up the check for the extra manpower.
The slots fill up fast because the average PennDOT job pays more than $42 an hour. Last week, PennDOT hired 24 officers to man detours during exit closures along Bigelow Boulevard. Officers usually work from 6 to 10 a.m. or from 3 to 7 p.m., when traffic is heaviest.
But don't expect them to leave anytime soon. Although adaptive traffic lights may wean PennDOT from human operators in the future, district traffic engineer Todd Kravits says his department wants to make sure the bugs are worked out first.
"We'd still want to have officers out there as we test these things out and build our level of confidence," he said. "Nothing's really going to replace people out in the field right now."
That's echoed by Pittsburgh Fraternal Order of Police president Michael LaPorte, who welcomed the improvements but said he doubts automation will replace men during trickier events, including Steelers games. But Mr. Smith said he believes his system could be just as flexible as one using humans.
"In theory, we can react to short-term things -- the emptying of a parking garage after a cultural event, the slowing of traffic after an accident," he said. "The design of our system emphasizes a real-time response on the order of seconds."
One day this week, an off-duty police detective waited on Grant Street for traffic to back from the Parkway East, watching workers tear away at the road. He didn't want to give his name, but he wasn't shy about the tedium of the job.
"You stand here and watch traffic. It's about as boring as it can be," he said. "But it's OT, and you're making extra money."
Andrew McGill: firstname.lastname@example.org or 412-263-1497.