© 2019 MENG Analysis

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project:

I-90 Two Way Transit and HOV Operations Stage 3

Sound Transit

Location:
Seattle, Washington
Estimated Cost:
$185 million
Service:
Constructability Review
Market Sector:
Transportation
Facility Specialty:
Highways, streets, parking lots
Designer:
WSDOT/Jacobs

PROJECT DESCRIPTION

 

The I-90 Two Way Transit and HOV Operations Stage 3 began construction after the completion of the first two phases that worked on the Eastbound and Westbound HOV lanes from Bellevue Way to 80th Ave SE. Phase 3 focused on the rest of the HOV lanes from 80th Ave SE to Ranier Ave.

 

Phase 3 required:

 

  • Structural interdisciplinary coordination between teams

  • Balancing

  • Testing

  • Risk assessments

  • Commissioning of ventilation

  • Fire suppression

  • SCADA

  • ITS systems - in order to maintain properly balanced existing systems until the transitional and new systems are phased in. 

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The focus of the constructability review was on the HOV lane to and from Seattle to improve the tunnel fire/life safety systems, improve Mount Baker Ridge and Mercer Island tunnels, bike path screening, as well as adjustments to accomidate for the East Link Light Rail project.