State 'Smarter Highways' plan: 300 signs over 40 miles

The state Department of Transportation has unveiled new "Smarter Highways" technology to alert drivers to traffic problems.

The new system features a network of sensors and electronic signs on northbound Interstate 5, Highway 520 and Interstate 90 that will automatically respond to traffic conditions to relay messages to drivers.

The 20-foot signs, which will be on 40 miles of state highways, will cost about $60 million. Of that, about $21 million will come from money earmarked for I-5 improvements under the Alaskan Way Viaduct project. The rest of the money comes from a federal grant.

Altogether, there will be about 300 signs spaced a half-mile apart. Each sign will depict the speed in each lane.

"Traffic engineers call it active traffic management, but it's really about making our highways smarter," said Transportation Secretary Paula Hammond. "This new system builds and expands on the advanced tools drivers are using today and takes them to the next level."

The electronic signs will automatically alert drivers to change lanes when an incident blocks traffic ahead or to adjust their speed before they reach slower-moving traffic. It will help reduce rear-end collisions, allow for earlier escape to alternate routes and smooth lane shifting caused by incidents like stalls or collisions.

The location of the smarter highways signs and when they will be operational:

• Northbound I-5 between the Boeing Access Road and I-90 in summer 2010.

• Highway 520 between I-5 and 130th Avenue Northeast in Bellevue in summer 2010.

• I-90 between I-5 and 150th Avenue Southeast in Bellevue in spring 2011.

Traffic engineers studied similar technology used successfully in European countries, including Germany and Great Britain, where it helped reduce congestion-causing collisions by as much as 30 percent.

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com