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Practical Design Peer Review

WSDOT has a long tradition of embracing practical solutions in its approach to developing and delivering projects to meet the transportation needs of the state. In that spirit we have developed additional tools, such as a peer review meetings, to aide in our response to the challenge of meeting the purpose and needs of projects at lower costs while still maintaining a safe high quality transportation system.

US101 Siebert Creek Fish Passage Project

Project  and need
The existing structure has been identified as fish passage barrier due to velocity, profile drop and debris accumulation. Eliminate restrictions to fish passage. Replace with fish passable structure and regrade the stream to eliminate restriction to fish passage.

Refined – Prevent or remedy the existence of fish passage barrier; restore or simulate stream.

Recommended idea
The peer review team recommended that a new bridge be constructed for the west bound lanes on the existing grade and remove the fish barrier to provide full bank width.

The benefits:

  • Lower construction costs
  • Easier to construct
  • Reduces project footprint
  • Reduces construction limits
  • Overall bridge length is reduced

Challenges :
Vertical alignment – bridge will be located in a sag vertical curve hence stopping sight distance will have to be carefully reviewed as will conveyance and treatment of runoff.

The savings:
By having less structure to build and an easier construction due to fewer spans the potential anticipated cost savings may reach over $8m and reduce the construction duration by 3 months.

SR 160 Southworth Ferry Terminal

Photo of Southworth Terminal and typical ferry terminal structure.
Purpose and need

The project addresses the need to preserve safety by preventing failures caused by seismic events. Other consideration include: maintain ferry operations, accommodating various transportation modes, meeting ADA accessibility standards and reviewing the septic/drain field priority.

The Southworth Ferry Terminal creosote-treated timber trestle, timber bulkhead and terminal building are aging and in deteriorating condition. The original facility was built in 1958 and is reaching the end of its usable service life. The objective of this project is to increase seismic resilience of the terminal to decrease the risk to the public during seismic events.

Recommended idea:
The peer review team proposed a smaller trestle for loading and unloading only and moving the terminal off of the trestle to an inland location.

The benefits:

  • Lower cost
  • Reduces risk to travelling public
  • Less overwater coverage
  • Eases drain field work

Pedestrians may have to travel farther to use restrooms and reduces parking.

The savings
Are due to elimination of a 6’ wide temporary pedestrian walkway and a temporary terminal during construction. Resulting in over $1 million saving, reduced construction time, and less construction in and over water.

I-5 Interchange Compact Roundabouts

Project and need
When rush-hour traffic at an Interstate 5 interchange near Ferndale created backups on the off-ramps that reached the mainline, local officials and WSDOT engineers knew they had to do something – and do it quickly and for a minimal amount of money. 

The Bellingham Herald ran an article  (pdf 108 kb), Aug. 7, about the successful partnership and project benefits.

Recommended idea:
The Whatcom County Council approved funding for a $300,000 plan in which WSDOT will install three compact roundabouts at the I-5 interchange with Slater Road, between Bellingham and Ferndale. The compact roundabouts will be located at the northbound and southbound I-5 ramps at Slater Road and at Pacific Highway and Slater Road.

The benefits: 
The analysis concluded that four-way stops would create even bigger traffic back-ups, especially at peak hours. Signals or full roundabouts cost between $1.5 to $2.5 million each, whereas the compact roundabouts will operate safely and efficiently and can be built in the existing paved area for about $100,000 apiece.

The smaller size allows compact roundabouts to be built more quickly with less disruption to traffic. It should take about two weeks to complete all three compact roundabouts once work starts in September. Work should be completed by early fall.