I-5 - SR 510 to SR 512 Congestion Management - ITS & Ramp Revisions

Ramp Meters between SR 510 and SR 512 were activated in May 2015. A list of ramp meter locations and an explanation of how they work is located here (pdf 144kb). This project is now complete.

This project is one of several that WSDOT has undertaken to improve traffic flow on Interstate 5 in Thurston and Pierce counties.

In this project, WSDOT installed "intelligent transportation systems (ITS)" devices that help WSDOT manage traffic and communicate real-time traffic conditions to the public. Devices installed include:

  • 2 ramp meters
  • 2 closed-circuit traffic cameras
  • 1 variable message sign and supporting electronic hardware

This project also widens the Mounts Road Gate access road on Joint Base Lewis-McChord (JBLM) from one lane to two lanes. The widened access road will complement work completed by WSDOT and Pierce County in 2013 that installed turn lanes and a new traffic signal at the interchange of Nisqually Road SW and the JBLM Mounts Road Gate near Interstate 5.

Revised I-5 Center Drive Interchange
This project also revised the I-5 Center Drive interchange, allowing for continued use from Joint Base Lewis-McChord.

Why is WSDOT revising the I-5 Center Drive Interchange, adding “smart highway” devices on I-5 near Carpenter Road, revising I-5 ramp meters in Nisqually and widening the Mounts Road Gate access road?

The current connecting road from Joint Base Lewis-McChord to Center Drive was originally built as an emergency access and was not intended for routine use. To allow the continued use of this road, the I-5 Center Drive interchange was revised.

I-5 Center Drive Interchange Revision map
View full size image (pdf 220kb)

View the I-5 JBLM Area Improvements - Project Map for a complete look at I-5 corridor improvements in Thurston and Pierce counties.

Project Benefits

The I-5 Center Drive ramp revision will allow JBLM personnel to continue to exit the base at Center Drive.
The cameras and ramp meters allow WSDOT to manage traffic demand. From a central traffic management center, WSDOT staff use the camera images to keep apprised of traffic conditions on state highways.

The images are used to call out emergency personnel, report traffic conditions through highway signs and radio messages, and monitor traffic flow. They are the same images you can use to know before you go.

Ramp meters manage traffic demand by controlling the number of cars that merge onto I-5 when congestion is heavy. This will help keep mainline I-5 moving.

The new technology will also allow WSDOT to offer travel times from Olympia to Tacoma.

The widened access road at the Mounts Road Gate will accommodate two-way directional traffic.