Expansion joint replacement
Thirty-seven deteriorating expansion joints on 10 bridges will be replaced -- 22 on the mainline and 15 on various ramps and express lanes -- on northbound I-5 from the South Boeing Access Road on-ramp to the Ship Canal Bridge.

Expansion joints are critical to the safe operation of bridges. They allow a bridge deck to expand and contract during changes in temperature. An expansion joint that fails can pop up into traffic.

Concrete panel replacement
Crews will remove damaged concrete panels throughout the length of the project. These panels are cracked beyond repair. After the panels are removed, the roadbed will be repaired as necessary with new gravel and then new concrete panels poured.

All concrete panels from near the West Seattle Bridge to near the express lanes ramp will be replaced. Select panels will be replaced between:

• South Boeing Access Road on-ramp to Corson Avenue South/South Michigan Street off-ramp.
• Cherry Street on-ramp to Mercer Street off-ramp (right lane only).
• Olive Way overpass to SR 520 off-ramp.
• Northeast 45th/50th Street off-ramp to Northeast Ravenna Boulevard.

Roadway grinding
Roadway grinding is one of the most cost-efficient and effective ways to improve the driving surface of aging concrete. However, grinding is a noisy operation.

Grinding removes a very thin layer of the concrete to reveal a new surface. This new surface improves traction for drivers and removes wheel ruts where water can pool.

Crews will grind between:

• South Boeing Access Road on-ramp to Corson Avenue South/South Michigan Street off-ramp.
• Olive Way overpass to the Harvard Avenue East on-ramp.

Repaving
Crews will repave the following ramps:

• Northbound I-5
  • Swift Avenue South off-ramp
  • South Columbian Way off-ramp
  • 6th Avenue South on-ramp
  • Olive Way off- and on-ramps
  • Mercer Street off- and on-ramps
  • State Route 520 off- and on-ramps
  • Northeast 45th Street off- and on-ramps
  • Northeast 50th Street off- and on-ramps
  • Northeast Ravenna Boulevard exit-only lane and off-ramp
• Southbound I-5
  • 6th Avenue South on-ramp
  • Mercer Street on-ramp
  • Northeast 45th Street off- and on-ramps
  • Northeast 50th Street off-ramp
• Express lanes
  • Mercer Street ramps
  • Northeast Ravenna Boulevard on-ramp
• Other ramps
  • South Columbian Way to 6th Avenue South

Repaving requires the removal of the top 1.5 to 2 inches of the existing pavement by milling it off. This can be unavoidably noisy work. After the asphalt removal is complete, the roadbed will be repaired as needed by excavating deep potholes and cracks and then placing new fill and gravel. Once repairs are complete, a new layer of asphalt will be placed.

Along ramps that are being repaved, various existing pedestrian ramps will be rebuilt to meet current Americans with Disabilities Act guidelines.

Safety barrier improvements
A safety barrier will be extended between the mainline and the collector-distributor lanes at Martin Luther King Junior Way South/State Route 900.

A damaged concrete barrier at the Mercer Street on-ramp will also be replaced.