Two years ago, the streets of Grapevine, Tex., like thousands of roads across America at rush hour, resembled a parking lot every afternoon. The town of 50,000 near Dallas/Fort Worth International Airport saw 300,000 outside vehicles pass through each day as drivers sought to avoid highway delays.
To solve the problem, city officials turned to Rhythm Engineering, a traffic consulting firm in Lenexa, Kan. Its proprietary InSync system blends real-time street monitoring with adaptive algorithms to do the seemingly impossible: not only speed up traffic but also make it safer.
Rather than preprogram single signals on timed loops or individual triggers, Rhythm rigs larger corridors with traffic-counting cameras, grouping cars into ad hoc motorcades that are sent through a series of green lights en masse. After each block of vehicles passes, adjoining side streets switch to green lights to move cross-traffic.
In Grapevine, a Rhythm project that programmed 52 intersections reduced stops in some areas by as much as 88 percent and wait times by as much as 45 percent. Rhythm estimates the amount of time and fuel saved to be worth $8 million annually. “Overall, it’s a beneficial system,” says Grapevine’s transportation manager Mike Pacelli, who notes that the city still struggles with sheer capacity limitations.
Nationally, Rhythm has rewired 700 intersections in 20 states. “We kind of view traffic as a real crisis situation,” says David Frankland, Rhythm’s president and chief operating officer. “Most people don’t realize the effect it has on the community in terms of fatalities, congestion, toxic emissions, fuel cost, and time wasted.”