I-5 - Olympia Area Southbound - Congestion Management

Project news

  • Crews will install new southbound I-5 ramp meters at four on-ramps between Lacey and Olympia.
  • WSDOT anticipates the ramp meters will be operational during late summer.
  • These ramp meters join other ramp meters serving the I-5 corridor in the Puget Sound region.

Needs & benefits

Multiple vehicles merging onto the highway at the same time contributes to southbound I-5 congestion between Lacey and Olympia. A platoon of merging vehicles will caused drives using I-5 to change lanes or slow down. This has a cumulative affect similar to damming a river that contributes to congestion.

Ramp meters pace the flow of merging traffic. A short wait at a traffic signal on the on-ramp helps break up the platoon of vehicles. When vehicles enter the highway in controlled intervals, those vehicles are less likely to disrupt highway flow.

Overall, highway drivers increase their average highway speeds and shorten overall highway travel times. Ramp meters also help reduce the potential for collisions when multiple vehicles merge onto the highway at the same time.


March 2019 – Project advertised for bidding
April 2019 - Project awarded private contractor
Spring/Summer 2019 – Construction
Fall 2019 – Project complete


Financial Data for PIN 300519Q
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $550
CWA $0
Total $550


Doug Adamson
WSDOT Communications

Brian Whitehouse
Lacey Project Engineer Office

I-5 Olympia Area Southbound Congestion Management project vicinity map