By guest blogger Bart Treece

A sky of blue, a sea of green and a river of red brake lights….OK… that’s not how it goes, but that’s what folks could be seeing this weekend, unless they plan ahead  for congestion.

Let me explain. There are so many things to do this weekend in Seattle, and sitting in traffic shouldn’t be one of them when you’d rather be cheering the Sounders on against Sporting KC, enjoying the Seattle Dog Show or watching the women of the Pac-12 battle it out on the hardwood. With so much happening it might be kind of tough to get to where you want to be on time without some preplanning.

What’s going on?

Our contractor crews will be closing all but one lane on the northbound I-5 collector-distributor, which runs parallel to the wider section of I-5 between I-90 and Madison Street. The collector-distributor or “C-D” as it’s known in traffic-talk, helps merge cars from I-90 to I-5 and downtown off- and on-ramps. Here’s some nifty animation that shows how vehicles will navigate through the work zone.

The closure is the fifth of nine in this part of I-5 to replace 26 worn and aging bridge expansion joints before they go bust, which would lead to flat tires, emergency closures and major headaches. It’s happened before, and it ain’t pretty.

Emergency repairs to a damaged expansion joint in Dec. 2013

Traffic tips

Plan your trips ahead of time and know before you go. Carpooling, taking transit, delaying or combining trips will help reduce congestion in the area for everyone. Use alternate routes. If you can, take the backdoor into downtown Seattle on SR 599 to SR 99. We often see free-flowing traffic on this under-utilized route during weekend closures ...just sayin’.

With heavy traffic expected on westbound I-90 into downtown, SR 520 might be a better cross-lake route. The I-90 express lanes will look good westbound, and will be open to all (both carpoolers and solo drivers) during times of high congestion (keep an eye on the highway signs). Sounders fans should expect some delays heading eastbound after the match, so hanging in Pioneer Square for an hour to let traffic settle down would be a good idea. To head north from SoDo, take SR 99 or use surface streets to access the Cherry Street on-ramp to I-5 or the 5th Avenue & Cherry ramp to I-5 express.

You can always see how traffic is or isn’t moving through the area on the Seattle Traffic page or with the WSDOT mobile app for iPhone and Android devices.

There’s really never a “good” time to tighten traffic, but we really appreciate your patience and understanding when we do have closures for construction. Knowing ahead of time and planning for congestion really helps keep people moving, and we appreciate everyone for chipping in.

By guest blogger Joe Irwin

We’ve probably all done it. Taken an on-ramp onto I-5 during rush hour thinking maybe this time it won’t be so bad only to run into a sea of red brake lights, and then subsequently cursing Henry Ford for inventing the automobile.

As most Washington drivers can attest, traffic congestion is becoming routine on certain sections of highway statewide. In addition to numerous projects to improve traffic flow, we analyze and report on highway trends.

We’ve been doing this for the past 12 years, but this year we took our in-depth review a step further and in a new direction. The idea is to provide a much finer level of detail in telling the story behind traveling on our state’s highways.

We recently released the 2013 Corridor Capacity Report, providing an unprecedented look at how transit and park and rides fit into the overall transportation scheme on our state highways, while making note of empty seats and parking spots along specific corridors.

This unused capacity on buses is a big deal because it shows us and transit agencies exactly where we can add more riders, park and rides and/or transit services to make things more efficient on the highways at reasonable costs.

According to the report, mass transit took more than 43,800 vehicles off the road each day in 2012, reducing daily carbon dioxide emissions by 674,700 pounds. Even so, our findings show we can improve transit use and reduce emissions by using the existing capacity we have and filling unused seats during the tail ends of the peak periods.

The report focuses closely on routinely congested sections of highway, which also allows us to figure out exactly where the problem areas are located. Traffic patterns differ during the morning and evening commutes, and determining where congestion is worst, when and for how long, helps us as we work to alleviate it.

As more and more people hit the roads each day, the corridor capacity report is providing us a new tool with which to decide the best ways of helping everyone get from Point A to Point B as efficiently and reliably as possible.