Tara Leitzell says the traffic lights on Ogden Avenue in Chicago are timed so drivers hit every red light.
“Whoever did that has a special dislike for commuters,” said Leitzell, who drives from her home near Ogden and Chicago Avenue to her job at a medical center in Lawndale.
CTA rider Betsy Roth complains that poorly coordinated traffic signals are at least partly responsible for CTA buses bunching up on Michigan Avenue downtown.
“If I miss my bus I can look up Michigan and see a caravan of buses going a block, stopping at red lights, going another block and stopping again,” said Roth, a marketing executive who lives in Lincoln Park. “Ten or 15 minutes later, three buses in a row show up.”
Who hasn’t been tempted to stomp off a bus that falls further behind schedule with every red light because it would be quicker to walk? Or who hasn’t sat behind the steering wheel waiting at a red light late at night when no other moving vehicle is in sight?
Badly timed traffic signals rank among the chief traffic complaints of commuters and lead to frustration, gridlock, wasted fuel, worsening pollution, lost productivity and road rage.
The good news is that Chicago transportation officials at the Traffic Management Authority are focusing on solutions and new technology–as if timing were everything.
By the end of 2006, about 60 more intersections will have signals that are interconnected and synchronized with other nearby signals, according to Yadollah Montazery, assistant director of the city’s Office of Emergency Management and Communications, which oversees the Traffic Management Authority. The upgrade will bring the total to about 460 intersections.
Synchronization involves sequencing the traffic lights to maximize traffic flow through a series of green lights.
About 2,000 of Chicago’s 2,800 signalized intersections have synchronized traffic lights.
Signal interconnects often include synchronization. But interconnects allow inclusion of cameras and sophisticated technology to monitor and improve in real time how well an intersection is working because the traffic signals are physically linked by fiber optic cables.
“Typically we have seen a 15 percent improvement in travel times on corridors where signals are interconnected,” Montazery said.
The federal government knows the tremendous benefit of interconnecting traffic signals, which is why it provides cities with 80 percent of the funding for design and construction, he said.
Chicago’s traffic management goal includes having the ability by the end of the year to remotely adjust the red-and-green cycles on about 200 of the existing 400 interconnected signals by using cameras positioned above the streets and computers inside the traffic authority’s headquarters in the West Loop.
More changeable message boards also are being installed alongside some of the interconnected signals so motorists will be alerted before they get to the problem areas–and take alternate routes.
Montazery said being able to adjust traffic signals in response to situations, rather than changing signal timings only at predetermined hours each day, will improve traffic flow around accidents, crime scenes and special events.
– – –
Tech helps traffic
Approximately 100 of Chicago’s 2,800 signalized intersections are equipped with actuated signals, said Brian Steele, spokesman for the Chicago Department of Transportation. Actuated signals use sensors buried in the pavement to determine how much red, green and green-arrow time to give based on where the traffic flow is heaviest.
Other types of “smart” traffic technology still need some tutoring. In 2001, Chicago tested self-setting traffic signals at a dozen River North intersections.
The signals were designed to gauge congestion and automatically adjust red and green cycles based on the traffic flow. But the experiment was stopped after several months because the system could not process the high volume of data quickly enough to relay instructions back to the traffic lights in a timely manner, city officials said.
— TRIBUNE
