Speed reduction on I-5 in Kent/Des Moines area begins the week of May 1

Adjustment will enhance safety near new construction zones in I-5 median

KENT – A lower speed limit and traffic shift on Interstate 5 in Kent and Des Moines will enhance safety for both highway construction crews and people driving through a newly established work zone of the SR 509 Completion Project.

The week of May 1, the Washington State Department of Transportation will establish a temporary 50 mph speed limit on southbound I-5 at the State Route 516 Kent/Des Moines interchange. The speed reduction will begin near milepost 150, or South 220th Street, and end near milepost 149, or South 240th Street. In addition to the 50 mph speed limit, lanes in both directions of I-5 will shift to the right to make space for a work zone in the median.

Traffic shift and lane closure details

There will be the following lane closures on I-5 at the SR 516 Kent/Des Moines interchange to allow crews to restripe and shift lanes:

  • 11:30 p.m. Sunday, April 30 to 6 a.m. Monday, May 1: Up to four lanes of southbound I-5 will be closed.

Once the traffic shift is complete and the roadway re-opens to traffic the new 50 mph speed limit will be in place.

Work zone details

  • People traveling on southbound I-5 will see new speed limit signs.
  • People traveling in both directions will see new signs warning of lanes shifting to the right and construction activity on the shoulders and median of I-5.
  • The temporary speed limit and traffic shift is anticipated to last through summer 2023.
  • WSDOT will work with the Washington State Patrol to manage enforcement of the new speed limit. Traffic fines are double in work zones.

The new temporary lane shift on southbound I-5 will create a safe work zone and provide the room crews need to continue construction of planned improvements to I-5 and the I-5/SR 516 interchange as part of the SR 509 Completion Project.

This is the second of two speed reduction zones on I-5. Another temporary 50 mph speed zone is in place northbound and southbound near the Fife curve between 54th Avenue East and Porter Way for the SR 167 Completion Project.

Benefits of speed reductions

Construction on high-speed, multilane roadways with high traffic volumes can increase risks to both construction crews and drivers. Reducing speeds encourages travelers to slow down, follow posted speed limit signs and remain alert while traveling through an active work zone.

WSDOT is reminding all drivers in work zones to:

  • Slow down – drive the posted speed limits, they're there for driver safety.
  • Be kind – construction crews are helping to keep travelers safe and improve the roadways.
  • Pay attention – both to workers directing traffic and surrounding traffic.
  • Stay calm – expect delays, leave early, or take an alternate route if possible; no meeting or appointment is worth risking a life.
  • Remember construction crew members are spouses, parents, children, siblings and friends – and they all deserve to go home safe at the end of their shift.

Completing SR 509

This construction work is part of WSDOT's SR 509 Completion Project which will build three new miles of roadway and completes the unfinished SR 509 in south King County. The new four-lane highway will become an important north-south alternative to the congested I-5 corridor between Seattle and south King County.

The work on I-5 for Stage 1b of the SR 509 Completion Project will be complete in 2025. The entire project will be complete in 2028.

Gateway Program overview

The Puget Sound Gateway Program combines the SR 509 Completion Project in King County and the SR 167 Completion Project in Pierce County to complete critical missing links in Washington's highway and freight network. These projects build important new connections to the state's ports, improve the movement of freight and reduce congestion on local roads and highways.

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