often drives home this way, stopping at Whole Foods. Yet today, the familiar route feels faster. Beside him, his iPhone logs his times between intersections. Smith, director of the in 麻豆村鈥檚 , not only feels a difference, he鈥檚 measuring it鈥攁nd he helped create it.
Over three months, his team crisscrossed streets in Pittsburgh鈥檚 East Liberty neighborhood, testing their pilot system, (Scalable Urban Traffic Control), which uses a hybrid stoplight bundled with video cameras and a Surtrac processor.
Here鈥檚 how it works: When the video cameras see approaching traffic, the Surtrac processor computes a plan for how all of the vehicles are going to move through, Smith says. The stoplight then follows Surtrac鈥檚 plan, streamlining traffic flow, and Surtrac shares the data with other stoplights to minimize cumulative delay for a larger area.
Smith began with a software model, simulating how a few strategic Surtrac stoplights would improve Pittsburgh鈥檚 downtown traffic. After successfully mastering this exercise, he looked for a real-world testing ground that became East Liberty.
The neighborhood was selected after Smith was stopped at a red light down the street from Whole Foods: 鈥淚 looked up and realized the lights had cameras.鈥� This pre-existing equipment made East Liberty a 鈥渓ow-cost site.鈥� Last year, the team drove the test area鈥檚 12 busiest routes, setting a benchmark. Three months later, they collected data again, with Surtrac scheduling the stoplights.
In results announced last September, the pilot reduced travel time by 25% and cut vehicle emissions by 21%. Smith plans to expand the pilot in Pittsburgh this year and, eventually, to other cities.
鈥擜aron Jentzen (DC鈥�12)
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