Portage Bay Bridge and Roanoke Lid Project 

Aerial view of Portage Bay construction

The Portage Bay Bridge and Roanoke Lid Project will replace the aging Portage Bay Bridge with a seismically resilient structure that includes improved bus/carpool travel and an extension of the SR 520 Trail. This project also builds a landscaped lid between Seattle’s Roanoke Park and North Capitol Hill neighborhoods.

Project materials

Community Construction Management Plan

The Portage Bay Bridge and Roanoke Lid Project’s Community Construction Management Plan (CCMP) describes what neighbors can expect during construction, the construction practices the contractor will follow, and how the contractor will avoid or reduce construction effects on neighborhood residences and historic properties. Our project contractor updates the CCMP throughout the project duration based on construction activities and public feedback.

Check out the Portage Bay Bridge and Roanoke Lid Project’s draft CCMP. The contractor will begin outreach to update the Portage Bay Project’s CCMP after the contract is awarded.


View the Portage Bay Bridge and Roanoke Lid Project’s Draft Tree and Vegetation Management and Protection Plan (TVMPP), which describes project-specific management practices to preserve, protect and avoid affecting trees and other vegetation within a project’s construction area. The plan identifies ways to limit effects on vegetation during construction and establishes an implementation plan to ensure best practices are followed.


We are committed to following noise regulations and using best practices to reduce noise generated by our construction. Daytime construction activities follow daytime noise limits set by the city of Seattle. However, some construction activities occur at night due to safety and traffic concerns. The city of Seattle grants a Major Public Project Construction Noise Variance that sets limits for the allowable level of nighttime construction noise.

Read the Portage Bay Project’s MPPCNV application to learn about nighttime noise limits and commitments.


The Portage Bay Bridge and Roanoke Lid Project’s Neighborhood Traffic Management Plan (NTMP) outlines planned traffic management measures (both temporary and permanent) within a project’s construction area. The NTMP also outlines some of the best management practices that will be used during construction to help reduce local traffic effects related to project construction.


Our project contractors must submit and follow a vibration monitoring plan. The plan identifies how construction activities will be carried out to stay within a contract’s vibration limits. The plan also shows the locations of digital vibration monitors. The contractor will prepare a vibration monitoring plan after the contract is awarded.


We strive to the keep the public informed about our project construction activities and effects. We do this through regular public meetings, neighborhood FAQs, community events, and digital communications.

Construction photos