Ann Arbor’s intelligent traffic system tames traffic
For all the Mishegas on self-driving cars in sunny, tech-savvy Silicon Valley, the future of the automobile could still live in a colder climate. At least Wolverine State hasn’t loosened its grip on the future of trafficking.
Ann Arbor is home to the University of Michigan, and with football games, Kid Rock concerts, and daily commuters, it gets a lot of traffic. In an average week, the city of 125,000 inhabitants swells to contain 200,000 people, most of whom travel by personal car. The city is exploring bus, commuter train and carpooling options to clean up its roads, but knows it can’t drive the car out of its home country anytime soon. She therefore turned to technology to manage her streets.
Intelligent Traffic Systems have been adjusting traffic lights and signs to mitigate traffic jams in real time for more than three decades, all over the world. Over 100 cities, including London, Santiago and Toronto, use the same car corraling program as Ann Arbor.
Now this technology is getting smarter — and it’s winning the battle. New figures from Siemens, co-owner of the Ann Arbor program with British company Imtech, show that the city’s more advanced software is seriously reducing local traffic.
Cities program your standard traffic light by observing traffic patterns for a few hours, extrapolating the needs of local vehicles, and then letting the lights do their job for years, if not decades. More advanced systems will be able to detect if a vehicle is stopped and turn on the green light to help it. The more advanced systems — like the one in Ann Arbor — will know how many vehicles are stopped, in which lane, and how many vehicles are descending the spike.
Ann Arbor’s adaptive traffic light control system has been playing God for more than a decade, but violin engineers continue to fine-tune its inputs and algorithms. It is now reducing weekday travel times on the affected corridors by 12% and weekend travel time by 21%. A journey along a busy corridor that took less than three minutes just 15 percent of the time in 2005 now falls below that mark 70 percent of the time. What convince the traffic engineers of Ann Arbor, who have just announced that they will extend this system to all its traffic lights in the city center and its busiest corridors.
To combat congestion, each signal skipped uses sensors or cameras built into the roadway to spot cars waiting at red lights. The signals send this information over the fiber optic network to the Big Computer at the traffic management base, which compiles the data.
This stuff works at a macro and micro level: if there are four cars lined up to cross an intersection one way and no car lined up to move perpendicular to them, the light may turn green for all four. But one network connected lights — like in Ann Arbor — will analyze the entire network and determine who to prioritize to get the most people to their destinations the fastest. Advanced traffic control systems can even predict delays and congestion build-up before they occur, based on the ebb and flow of commuting.
The system knows when to fire the change. “People are freaking out a bit if the signal is really different from yesterday or different from what it was five years ago,” says Richard Wallace, who heads the transportation systems analysis group at the Center for Automotive Research. . change the light patterns, not reshape the whole shebang from one hour to the next.
“If there is an abnormal amount of demand, this is when you can expect someone to step in and release the system, and allow them to respond on a wider range of parameters,” explains Luke Liu, a traffic engineer who manages the city’s signal. system.