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Urban Freight Lab Study Examines Freight Related Impacts Caused by West Seattle Bridge Closure

Urban Freight Lab Study Examines Freight Related Impacts Caused by West Seattle Bridge Closure
July 2, 2022   //   

As part of the University of Washington Urban Freight Lab,  researchers Dr. Anne Goodchild, Dr. Giacomo Dalla Chiara, Nota Goulianou, and Şeyma Güneş have published Understanding and Mitigating Freight-Related Impacts from the West Seattle Bridge Closure, a report on a study of the closure of the West Seattle High Bridge during 2020-2022.

The report documents the impacts of the closure on freight flow, businesses, and carriers, explores current freight movements and quantify freight demand, and identifies mitigation strategies for freight flow to and from West Seattle, both during the bridge closure and beyond. 

In the conclusions section of the report the study states:

The research team used multiple measures to document the impact of the West Seattle high bridge closure on freight flow in and out of the West Seattle peninsula—a closure that coincided with shutdowns and slowdowns related to the COVID-19 pandemic and its own economic and traffic follow-on effects. Interviews and surveys with 19 local businesses and carriers performing deliveries and pick-up in the study area including parcel delivery carriers, food and beverage carriers, supermarkets and restaurants, retailers, manufacturers, the Port of Seattle and five neighborhood and local business associations reveal the following key impacts.

On restaurants and supermarkets:

  • While supermarkets did not report major changes, smaller food establishments like restaurants and cafes did report important delivery disruptions: cancelled, delayed, and incomplete deliveries.
  • To cope with these disruptions, small food establishments reported having to pick up goods themselves from supplier locations, relying on smaller vehicles, such as personal cars or business vans, to do so; having to move their supply delivery destinations to locations off the peninsula; and/or having to buy their supplies from local WS supermarkets.
  • Businesses reported difficulties in retaining current employees and hiring new employees due to increased commute times.

On carriers:

  • Decreased restaurant demand in the pandemic led to reduced delivery volume to food and beverage businesses on the peninsula, leading in turn to food and beverage carriers both delivering less frequently and consolidating their deliveries by delivering to more customers per route, also reducing the number of routes performed.
  • In contrast, increased e-commerce demand in the pandemic meant rising parcel volume, leading parcel carriers to increase the number of routes serving the peninsula due to both the increased pandemic- related demand and the bridge closure impacts, including mounting traffic delays at access points.

On industry:

  • Port and industry operations did not seem to experience major disruptions as they were still authorized to use the lower bridge to cross the Duwamish Waterway.
  • That said, there were reports of lower bridge congestion from container trucks lining up at the port gates waiting to enter the terminal.

On retail, service and other establishments:

  • Service vehicles from outside the peninsula sometimes refused to serve establishments on the peninsula citing longer drive times with the bridge closure.
  • Smaller and larger retail and service establishments reported difficulties in hiring new employees in the wake of increased commute times after the bridge closure.
  • Some smaller businesses reported losing non-WS resident employees due to increased commute times after the bridge closure.

To help with data-driven decision making, the team developed a Freight Trip Generation (FTG) model that estimated at approximately 27,700 the daily number of freight vehicle trips in the study area across all activity types and to residential, commercial, and industrial buildings. Of those 27,700 daily freight deliveries and pick- ups, 74 percent are generated by the West Seattle peninsula. And of those deliveries and pick-ups generated by the West Seattle peninsula, 94 percent are to residential buildings. Significantly, the FTG data are not intended to illustrate changes in freight trip generation because of the bridge closure and/or the pandemic.

The team then analyzed a host of variables on each of the study area’s 13 residential and industrial neighborhoods to determine the relative impact of the bridge closure on each neighborhood. The most impacted neighborhoods were North Admiral, Genesee, Alki, Seaview, Gatewood and Fairmount Park. These neighborhoods have the largest share of FTG often performed by vehicles that are not allowed to use the lower bridge and experienced the longer re-route times.

Given these conclusions, what freight strategies could help mitigate the impacts of the bridge closure?

The short-term mitigation strategies below largely center on expanding lower bridge access while taking steps to ensure the expanded access does not impede the free flow of traffic. These steps could include:

  • Granting bridge permits to small businesses. As noted in the key findings, smaller food and service establishments surfaced in surveys and interviews as those most impacted by the bridge closure. These businesses often used smaller freight and personal vehicles to perform pick-ups and deliveries to overcome delivery disruptions. Granting these establishments lower bridge access would support their operations and reduce the negative effects of delivery disruptions.
  • Granting bridge permits to parcel carriers. The FTG modeling showed that most daily freight trips were home deliveries, including food and parcel deliveries. These deliveries were often performed with vans and personal vehicles. Allowing parcel delivery vehicles to use the lower bridge would reduce vehicle miles traveled by reducing the need for these vehicles to re-route to south access points.
  • Making permits time-based, (e.g., morning/afternoon only) to avoid peak traffic congestion and stagger lower bridge use throughout the day.
  • Staging container trucks. Container trucks accessing terminals T-5 and T-18 were reported to create frequent back-ups on the lower bridge. To assure free flow on the bridge, container trucks could be staged along Marginal Way, with a system of traffic lights, and allowed lower bridge access only when the trucks ahead have checked through the terminal gates.
  • Promoting zero-emission vehicles. Lower bridge permits could be given to establishments that use electric vehicles to perform deliveries and pick-ups to mitigate environmental impacts from the bridge closure, such as increased driving times with re-routing etc.

The long-term mitigation strategies below largely center on efforts to support local businesses both the supply and demand side. These steps could include:

  • Creating a centralized receiving station. Smaller businesses, especially food establishments, reported experiencing myriad delivery disruptions in the wake of the bridge closure. Giving larger vehicles carrying deliveries for multiple smaller WS establishments a centralized receiving station in a location closer to the businesses on the peninsula would allow carriers to deconsolidate their deliveries and stage goods until the small businesses or third parties (e.g., cargo bike delivery companies) could cover the last mile. This could increase delivery density for carriers, thereby reducing delivery delays and guaranteeing businesses timely access to their deliveries. It also removes the need for businesses to use smaller vehicles and vans to pick up goods off peninsula and lessens congestion on the lower bridge.
  • Creating a shared freight vehicle fleet. Disruptions caused by delivery delays led several establishments to use personal vehicles to perform deliveries and pick-ups, sharing a small number of lower bridge passes given to business associations. To increase vehicle utilization and reduce the total number of vehicles used, a fleet of smaller, zero-emission electric commercial vehicles could be procured and shared across multiple businesses and given a lower bridge pass.
  • Taking steps to increase the WS customer base. Businesses reported plummeting consumer demand in the wake of the concurrent COVID-19 pandemic and the bridge closure, particularly those customers coming from off the peninsula, such as tourists and weekend or special events visitors. While businesses report the local customer base grew stronger, they see the need to regain the off-peninsula customers lost. To support smaller businesses several strategies could be pursued to rebuild both the local and off-peninsula customer base:
    • Promote access to WS by bicycle and other micro-mobility modes in partnership with local businesses to attract new customers.
    • Encourage “Stay Local” and “Shop Local” campaigns to support local businesses and keep trips contained within the peninsula.
    • Deploy a parcel locker system at local businesses that receives packages from multiple carriers to increase foot traffic at local commercial areas on the peninsula. This could also increase delivery density and reduce the number of home deliveries.

Any of the above short- and/or long-term strategies could be considered to mitigate the effects of the West Seattle bridge closure on peninsula residents, carriers and businesses.