Seattle is spending $651,000 on traffic-network-control software that adapts to major incidents and would enable better signal-timing citywide.

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The Seattle Department of Transportation (SDOT) and technology firm Siemens say they’ve reached a deal for traffic-light software that will help the city react to freeway backups, a viaduct crash, or crowds leaving a baseball game.

The new system, called Concert, should be running by July, said Annie Satow, a Siemens spokeswoman. It will be installed at the city’s traffic-control center on the 37th floor of the Seattle Municipal Tower.

This isn’t the much-touted “adaptive-signal timing” that changes each intersection’s green-light patterns minute-by-minute, when vehicles arrive. But Concert will allow adaptive signals down the line, said Mark Bandy, SDOT traffic operations director.

For the first time, the city will be able to import external data, such as highway vehicle volumes from the Washington State Department of Transportation, and Concert will react by giving longer green lights to city streets near highway exits.

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On baseball nights, signals in Sodo could flip to postgame mode sometime before the ninth inning. Seattle Center streets would be coordinated for music fans who leave McCaw Hall. Or at 9 p.m. on New Year’s Eve, downtown signals would show more green where the Interstate 5 Union Street ramp spills into the city grid, relieving backups at the freeway, to name three examples Bandy gave.

Adaptive signals are coming to Mercer Street and its South Lake Union tributaries first, probably in the third or fourth quarter this year, he said. Street-level video and electronics must be installed first.

The city is paying $651,000 for Siemens software.

Signal-timing improvements were a core promise in last year’s voter-approved Move Seattle property-tax levy, which earmarks $13 million, in addition to the $1 million Mercer project, to upgrade at least five corridors per year for the next nine years. Several downtown streets lack even a magnetic, car-detecting loop in the pavement, so their stoplights run strictly on a clock.

Adaptive-signal systems already control 197 intersections in Bellevue, using signal software by TransCore, a competitor that also develops electronic toll systems.

Bandy said the Siemens system will give on-duty traffic engineers more time to issue electronic driver alerts, or to juggle multiple incidents and events.

Siemens said Seattle would join its Center of Excellence Partnership, making the city a laboratory to try technologies.

“Surrounded by water and mountains, Seattle’s narrow north-to-south geography creates unique and challenging traffic situations,” said a statement by Marcus Welz, president of Siemens Intelligent Traffic Systems.