Friday, June 5, 2020

Raising Interstate 5 at Berkeley Street

By Cara Mitchell

Construction on the project that widens Interstate 5 past Joint Base Lewis-McChord and Lakewood will soon reach new heights.

This summer, both directions of I-5 will be raised almost 14 feet at the Berkeley Street interchange. As explained in a previous blog, this design change will eliminate the need of a 1950s-era water pump at this location. Currently, the existing interstate sits below the water table and the old pump keeps water off the lanes of I-5. The new design installs modern drainage systems, eliminating the need for a pump.

This work was scheduled to begin in April, but when construction work was paused due to the Stay Home, Stay Healthy order, we had to adjust the timeline. Now that construction is being allowed to move forward, the project is kicking back into gear.

Here is a quick recap of work completed in early March, which set the stage for what is to come:
  • March 2: The new Berkeley Street overpass partially opened to travelers.
  • March 6-7: Crews removed the old Berkeley Street overpass, allowing this section of I-5 to be widened.


  • March 14-16: The Berkeley Street on-ramp to northbound I-5 opens from Tillicum.

Traffic shift – what to expect
So how does one raise the elevation of a major interstate that carries on average 140,000 travelers a day? In short, by stages. When the old Berkeley Street overpass was removed, construction crews began widening northbound I-5 at Berkeley Street.

Once that work is finished, the existing three lanes of northbound I-5 will move on to this new section of highway. When that happens, lanes of northbound I-5 will actually sit higher than the southbound direction.
Once finished, all three northbound I-5 lanes will shift to the right, on to new asphalt
approaching the Berkeley Street overpass.

Lanes of southbound I-5 just past the Thorne Lane interchange will also move. There will be approximately 3 weeks in between each directional traffic shift. Once in place, both directions of I-5 will be temporarily placed next to each other with narrowed lanes and shoulders as they pass under the new overpass. We will keep people moving by maintaining three lanes of traffic in both directions during construction. The graphic below shows what the temporary lane configuration will look like:

As widening work advances, the northbound lanes will remain in the same place, while southbound lanes will shift to the right. At that point, crews will complete widening in a median work zone, located under the Berkeley Street overpass.

Safety first
Recognizing this is going to be a new experience for travelers through this area, we, with the support of the Washington State Patrol, temporarily lowered the speed limit from 60 mph to 50 mph through this work zone. It is a necessary and prudent step to keep travelers and construction crews safe during this work. In addition to raising the profile of I-5, there will be on-going traffic shifts as work progresses at the new Berkeley Street interchange.

The temporary speed limit reduction will be in place through December 2020. Please continue to watch your speed in work zones and give construction crews the room they need to finish this project safely.

When will this work begin?
Unfortunately, our magic 8 ball hasn’t been necessarily accurate these days. Tentatively, this traffic shift is scheduled as early as mid-June. Factors playing into the timing of the northbound I-5 traffic shift include:
  • Pierce County moving to Phase 2 "Safe Start" plan
  • A new safety plan for "medium risk" work has to be submitted by the contractor and approved by us before the work can proceed
  • Shifting travel lanes is weather sensitive work
Once a firm date is known, we will share it with you at www.TacomaTraffic.com.

With all of the closures and detours, planning for extra travel time during your commute is highly advised. We will work through this next phase of construction as efficiently and quickly as possible. We appreciate your continued patience while crews finish this work.