WSDOT opens Seattle express lanes

Washington State Department of Transportation’s (WSDOT) newly automated Interstate 5 express lanes in Seattle have been successfully implemented. On Monday (July 23), state engineers activated the system that streamlines the way the agency switches the reversible express lanes. A switchover, from one direction to the other, which used to take up to an hour, is now scheduled to take just 15 minutes. On Monday, it took 13 minutes and 39 seconds. The US$6.6 million automated express lanes project, which was primarily funded by the federal government, is a key part of the ‘Moving Washington’ program; a strategy to fight congestion by using the latest technology to maximize the efficiency of the existing highways infrastructure.

The newly automated system uses: 45 new CCTV cameras, new variable message signs (VMS), new controllers, new signal and data cabinets, two new highway advisory radio stations and dozens of miles of underground fiber lines and Ethernet connections, in order to reduce the time it takes to switch the express lanes and communicate information to drivers. Engineers at the Traffic Control Center in Shoreline can now verify that the gates are closed and that signs are working and displaying the right messages. However, one engineer will still drive along the entire 11.2km (7 miles) corridor for a final visual inspection, as a safety precaution.

Paula Hammond, State Secretary of Transportation, noted, “Anyone who drives I-5 midday knows how frustrating it is to be stuck in traffic and see the express lanes empty during the switch. We’re putting cars into those lanes for an additional 45 minutes.” Translated into vehicles, it means an extra 900 vehicles per day during the week and an extra 1,000 vehicles per day over the weekend. Mainline congestion will improve as more vehicles move into the express lanes, and engineers estimate drivers will save about six minutes on every trip between Albro Street and Northgate. Morgan Balogh, WSDOT traffic engineer, commented, “For years, we had a team drive through and manually switch each of the 23 signs and close each of the 23 ramps. That took up to an hour most of the time. We were held hostage by the antiquated communication systems that had been in place since 1965. Now it’s a virtual drive-through.”

25 July 2012