US 2 Westbound Trestle Study - Study concepts

An expert panel consisting of traffic engineers, managers, planners, law enforcement, transit and freight representing different Snohomish County communities and agencies began by evaluating several dozen different replacement concepts. Most were immediately eliminated due to the high cost of rebuilding portions of I-5 to accommodate new or improved connections with US 2.

Two representative concepts emerged as the most feasible to accommodate traffic in year 2040.

  1. A new four-lane trestle with three general purpose lanes and one HOV lane for carpools and buses.
    This map shows a four lane trestle concept. The far left lane would be designated as HOV or another type of managed lane. The remaining three lanes would be open to all traffic. The HOV lane would end near I-5 and exit to Hewitt Avenue in Everett.
    The above map shows a concept of a four-lane westbound trestle. The far left lane would be designated as HOV or another type of managed lane. The remaining three lanes would be open to all traffic. At the I-5 interchange, the HOV lane would end and take a new exit ramp to downtown Everett. One of the general purpose lanes would also exit to downtown. Both of these lanes would descend and travel under the existing eastbound span before touching down near Hewitt Avenue. The ramps to northbound and southbound I-5 would each remain close to their existing locations. In this concept, both ramps would have two lanes that merge before entering I-5.
     
  2. A new trestle with three general purpose lanes, one of which becomes a short HOV/bus bypass lane at the I-5 interchange.
    This map shows a three-lane trestle concept for westbound US 2 as it approaches Everett. All lanes would be open to traffic, but the far left lane would become an HOV, bus or managed lane bypass as it transitions to an on-ramp to southbound I-5.
    The above map shows a concept of a three-lane westbound trestle. All lanes would be open to all traffic. At the I-5 interchange where the lanes transition to ramps, the far left lane would become an HOV or managed lane bypass. The middle and right lanes become ramps to downtown Everett, southbound I-5 and northbound I-5. The ramps would remain close to their existing locations, but more lanes would be available on the ramps to Everett and I-5.

Evaluation results

Prior to developing and evaluating the two concepts, project and traffic engineers forecast the amount of traffic expected on westbound US 2 in the year 2040. The forecast used projected population and business growth, and transit plans. This includes Community Transit’s long-term plans and Sound Transit’s planned light rail extension to Everett. The full evaluation results are available in the planning and environmental linkages study.

Key takeaways:

  • Highway congestion: Increasing the capacity of the westbound trestle does not alleviate congestion during the morning peak hours. Increased demand generated by a larger trestle could not be accommodated by I-5 and resulted in longer travel times across the westbound trestle.
  • Three-lane trestle: A three-lane trestle would provide enough room for the traffic expected in 2040, if congestion is addressed on the highway network.
  • Managed lanes: Managed lanes such as transit, HOV, express toll, or peak-use shoulder lanes could provide people with an option to bypass congestion and potentially improve conditions on I-5.
  • Walk, bike, roll: A long-term solution for the westbound trestle would provide an opportunity to create a valuable active transportation corridor between communities east of the Snohomish River and downtown Everett.
  • Mode share: The percentage of HOV and transit vehicles on the corridor during morning commute hours is expected to be less than 9% in 2040. Transit providers would need to include or increase service plans to give people a choice beyond single-occupancy vehicles and ensure service is coordinated with local and regional land use planning.
  • Environmental considerations: Environmental conditions are unlikely to serve as key differentiators among trestle alternatives. Potential adverse effects on sensitive areas and requirements to avoid, minimize or mitigate environmental effects will be key considerations in developing a long-term solution.