Returning ta the "Emerald City" yesterday, blew right through this choke point. Sure is a fucked up spot! Traffic generally chokes down ta three lanes heading south, from six, with exits and entry ramps before ya hit the sweet/sour spot!

The intersection of Interstate 5 and US 101 in Olympia is the site of an expansion bridge joint repair that takes place over two weekends in September 2014. Drivers will see reduced lanes of traffic on I-5 over both weekends. (WSDOT Photo)

Major I-5 closure to hit drivers with weekend plans; 14-mile backups expected

BY Chris Sullivan  on September 10, 2014 @ 6:39 am (Updated: 10:35 am - 9/10/14 )

In KIRO Radio's Chokepoints series, we take a closer look at the traffic issues plaguing commuters in the Puget Sound region.

One of the south Sound's biggest chokepoints is going to be even worse over the next two weekends as the state performs major surgery on I-5 near the Capitol campus in Olympia.

If you drive between Seattle and Portland, or just like to head over to the coast, you know what a nightmare it can be hooking into Highway 101 just past Capitol Lake. It routinely backs up, especially on Friday nights and over weekends.

It's going to get worse starting Thursday night. The state is about to replace a 171-foot long expansion joint on the I-5 bridge just before the 101 interchange.

"We're talking about the possibility of miles and miles and miles of stop-and-go traffic through the Olympia-area," said Washington State Department of Transportation spokesman Doug Adamson said.

To get ready for the two weekend closures, the state will need to restrict lanes Thursday night and close several on and off ramps to I-5 in the area. Then over both weekends, I-5 will be reduced to two lanes during the day and only one lane at night in both directions.

"The worst case (scenario) is ugly," Adamson said. "We could even see a southbound backup of up to 14 miles."

It's also going to spill over onto Highway 101 approaching I-5. Approximately 276,000 cars use that stretch of I-5 every weekend. Another 190,000 cars use 101 heading to I-5 on a typical weekend.

Drivers will have to be a part of the congestion solution. Adamson's best advice is to travel before 10 a.m. or after 8 p.m.

Unlike the recent I-90 closures, there is no real alternate to getting around this construction. I-5 is it for drivers heading south, unless they want to try some two-lane roads and smaller highways.

The state is even suggesting travelers consider taking the train.

Road work starts Thursday night with some preparation closures, but officially kicks off at 10 p.m. Friday night, when I-5 will be down to just one lane in both directions.