What are the key features of the Eastside Transit and HOV Project?
The Eastside Transit and HOV Project will complete and improve the 8.8-mile HOV system from Evergreen Point Road in Medina to the SR 202 interchange.
The improved six-lane corridor will include two general-purpose lanes and one transit/HOV lane in each direction.
Key features include:
What will the improved Eastside corridor look like?
|SR 520 near 108th Avenue NE (looking east)|
|92nd Avenue NE transit stop (looking west)|
|Evergreen Point Road transit stop (looking west)|
|Regional bicycle pedestrian path and Points Loop Trail (north of highway)|
Cost estimate summary: Yarrow Point Interchange at 92nd Avenue NE (Nov. 8, 2011)
In November 2010, WSDOT awarded a $306 million design-build contract for transit, HOV and environmental improvements on the Eastside. Eastside Corridor Constructors (ECC), the design-build contractor, is responsible for final design and construction of the new highway, fish-passable culverts, transit features, lids and interchanges.
ECC’s construction plans include design concepts developed by WSDOT and local communities as part of the Eastside Community Design Collaboration that took place from September 2008 to March 2009. As part of this process, WSDOT and local communities agreed on a roundabout design at the 92nd Avenue Northeast interchange. Construction is currently under way based on these design plans.
In November 2011, WSDOT responded to a public disclosure request from the town of Yarrow Point regarding cost estimates to redesign the interchange at 92nd Avenue Northeast. The materials we provided contained two cost estimates: a preliminary cost analysis prepared by WSDOT and a “rough order of magnitude” from ECC.
WSDOT’s estimate was preliminary and based on several assumptions that did not include design changes to key structures that the contractor identified would be necessary. Additionally, WSDOT’s estimate did not include key schedule and construction risks, which are used by ECC to estimate the affect to project schedule and budget that major design changes would have.
These estimates are summarized below.
WSDOT preliminary cost estimate
ECC “rough order of magnitude” estimate
|Design changes that assume structural changes would not be necessary
|| Avoids changes to key structures:
• The 92nd lid structure would not be affected.
• The regional bicycle/pedestrian tunnel would not be not affected.
• Four walls would not be affected – lid pier wall, westbound mainline walls, westbound off ramp walls and the bike/pedestrian path walls.
| Construction costs
|| • Assumes construction of a redesigned interchange would result in reduced construction costs.
• Does not include schedule or construction risks.
• Estimate includes quality assurance and scope development.
|Design changes, assuming structural changes would be necessary
||Based on advanced engineering, acknowledges necessity for structural changes:
• Geometric changes to widen the roadway and drop-off area will affect loading, and require the lid superstructure to be redesigned.
• The pedestrian tunnel may be able to be shortened but ECC would need to redesign two walls if the design change was made.
• Accommodating the space needed for vehicles to turn left from the off-ramp would require more structural support to handle the additional loads.
| Schedule risks
||• New design would affect budget and schedule up to two months for planned work activities from fall 2011 to 2012.
• Activities include relocating the westbound off-ramp from SR 520 at 92nd Avenue Northeast to begin work on the east half of the new lid structure.
• These schedule risks are a necessary component of project management.
|Construction and risks
||• Includes construction elements, maintenance of traffic, utility modifications (utilities have already been relocated for the roundabout design), and risks during construction.
It is important to us that the final product meets the needs of the local communities as well as serves the region’s users. That is why WSDOT is proud of its long-term coordination with residents and elected officials in Yarrow Point for over 14 years to develop and design the new SR 520 corridor.
WSDOT is hopeful and confident that we can work together to address Yarrow Point’s concerns. We appreciate the partnership we’ve had with Yarrow Point and other Eastside communities over the years, and believe our coordination has resulted in a better project.
Please feel free to contact us at SR520bridge@wsdot.wa.gov with any questions.