Congestion Relief in Store for Travelers on I-5 Between Chehalis and Centralia

Map of I-5 corridor between Centralia and Chehalis in Lewis County, WA indicating project location. Photo courtesy: Washington State Department of Transportation

Submitted by Washington State Department of Transportation

Interstate 5 travelers in southwest Washington will soon experience improved travel times and reduced congestion during their daily commutes.  

Starting Monday, June 3, the Washington State Department of Transportation’s contractor, Northeast Electric, LLC., will begin work to install new ramp meters at multiple I-5 on-ramps between Harrison Avenue in Centralia and Southwest Parkland Drive in Chehalis.

“During peak evening travel times, the on-ramps to I-5 become a choke point as several drivers try to merge onto the freeway at the same time,” said Project Engineer Jennette Queen. “Ramp meters will help improve travel times and safety by breaking up traffic and allowing smoother merging onto the highway.”

Northbound I-5 ramp meter locations

  • Exit 76 – 13th Street (on-ramp)
  • Exit 77 – State Route 6 (on-ramp)
  • Exit 79 – Chamber Way (on-ramp)

Southbound I-5 ramp meter locations

  • Exit 77 – SR 6 (on-ramp)
  • Exit 79 – Chamber Way (on-ramp)
  • Exit 81 – SR 507 Mellen Street City Center (on-ramp)
  • Exit 82 – Harrison Avenue (on-ramp)

How ramp meters work

Ramp meters are traffic signals that operate according to real-time conditions on the highways and ramps. The traffic signals provide consistent gaps in on-ramp traffic, preventing multiple vehicles from entering the highway at the same time. More efficient merging allows drivers to continue traveling smoothly and keeps traffic flowing at highway speeds. Ramp meters also reduce the potential for collisions by 30 percent.

How to use ramp meters

Drive the vehicle up to the white stop line to trigger the ramp meter. If the light is red, stop at the white line. When the light turns green, accelerate and merge onto the highway. Most ramp meters allow only one vehicle to proceed with each green light, creating a four- to 15-second delay between cars entering the highway. 

On-ramp delays

While ramp metering benefits drivers already on the highway, it can produce delays for drivers merging onto the highway. Unlike other states, ramp meters in Washington are not set to run during a scheduled time of day. Rather, WSDOT ramp meters adapt and operate based on real-time traffic conditions on the freeway. Additionally, WSDOT traffic crews will fine-tune ramp meter operations and closely monitor traffic at each ramp following activation.

WSDOT’s goal is to balance the needs of drivers merging onto the highway with the needs of drivers already there.

Know before you go

People can receive real-time travel information by signing up to receive email updates and text alerts or by downloading the WSDOT mobile app.

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