WSDOT buys 11 days a year on I-5

By guest blogger Jamie Holter

The I-5 express lanes run 9.5 miles and
provides extra capacity in the direction of travel.
Wait, what? How is that possible? Ok, ok, we’re not actually “buying” 11 days. We’re more like saving a bunch of time that adds up to 11 days a year. Let me explain.

You know those express lanes we have on I-5 that run through Seattle? It used to take several people up to an hour to switch all the signs and gates by hand just to reverse the direction of traffic. That meant there was nearly an entire hour when traffic couldn’t use the express lanes. But not anymore.

The express lanes are now automated. Engineers can now reverse the direction of traffic from a desk in Shoreline in just 15 minutes. Fifteen minutes! That’s a savings of 45 minutes every day, and that adds up to an extra 11 more days of access to the express lanes.

The express lanes run southbound from 5 to 11 a.m. Monday through Friday. At 11 a.m., a traffic engineer uses the 45 new cameras to visually review all 23 access ramps to confirm no vehicles are present. They then use desktop computers to communicate with new gate controllers and sign connections to close the express lanes. After a team pulls the express lane dragnet and completes a safety sweep, the engineer then opens the lanes northbound at 11:15 a.m.

The same system will be in place on weekends with the closing time scheduled for 1:30 p.m. and the reopening at 1:45 p.m.

Engineers estimate that an extra 900 to 1000 vehicles will have access to the lanes and it will save the average midday driver nearly six minutes from Albro to Northgate. That will be a big help to businesses like plumbers, delivery truck drivers and others who make a living driving Puget Sound during the day.