Research News

Curb Allocation Change Project

Seattle has experienced a rapid increase in ride-hailing trips by transportation network companies (TNCs) such as Uber and Lyft. That increase has raised broad concerns about congestion, safety, and effective curb use. In response, this study evaluated a strategy of increasing passenger loading zone (PLZ) spaces to manage TNC driver stops and improve traffic flow when passengers are picked up and dropped off in the South Lake Union area of Seattle.

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I-405 Express Toll Lanes Analysis: Usage, Benefits, and Equity

This study examined how the I-405 express lanes—the Washington State Department of Transportation’s (WSDOT) newest dynamically tolled facility—are used, the benefits they provide to users, and how these benefits are distributed among different groups of noncommercial users. The project provided unique insight into facility usage patterns and equity impacts associated with different income and geographic groups.

Airport Infrastructure Resource Manual

To be well prepared for a major earthquake or other substantial hazard event, the state must have a complete inventory of existing airport facilities and understand their potential for emergency usage. This project created a comprehensive inventory of airport characteristics and surrounding facilities at 23 general aviation airports in Western Washington that will increase the state’s emergency preparedness and overall safety for Washington residents.

Material Application Methodologies Guidebook

Roadway maintenance agencies are challenged in winter to cost-effectively provide a high level of service and improve safety and mobility, and they strive to use the most recent advances in the application of maintenance materials, equipment, and sensor technologies. The goal of this research was to create a synthesis of best management practices for deicing application rates and material application methodologies.

Field Analysis of Wood Guardrail Post Decay

Wood guardrail posts can be inspected for decay by using a non-destructive testing technique called stress wave timing (SWT). This project investigated the integrity of wood guardrail posts in strategic locations of Washington state using SWT and then analyzed the data to determine factors that may lead to increased wood decay rates. The researchers determined that high climate index, , a measure of a region’s average annual rainfall and temperature, and poor preservative retention levels were associated with high decay rates. WSDOT will be able to use the results of this project in considering approaches to managing its guardrail assets in the future.

Seattle Center City Alley Infrastructure Inventory and Occupancy Study 2018

The Supply Chain and Transportation Logistics (SCTL) Center at the University of Washington conducted an alley inventory and truck load/unload occupancy study for the City of Seattle. Researchers collected data identifying the locations and infrastructure characteristics of alleys within Seattle’s One Center City planning area. The resulting alley database includes GIS coordinates for both ends of each alley, geometric and traffic attributes, and photos. The researchers developed alley management recommendations to promote safe, sustainable, and efficient goods delivery and pick-up.

I-35 FRATIS Impacts Assessment

This project evaluated the impacts of roadway performance information delivery efforts on freight operations in Texas. A freight advanced traveler information system (FRATIS) was deployed in the form of the I-35 Traveler Information during Construction (TIDC) system in Dallas, Texas, in association with major reconstruction work on I-35. The evaluation focused on the impacts of delivering the TIDC information to trucking companies. Both participating trucking companies reported receiving benefit from the construction delay information.

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Bio-Based Renewable Additives for Anti-Icing Applications (Phase II)

Maintenance agencies are constantly seeking an alternative to chloride-based deicing salts, one with maximum anti-icing efficiency and minimum drawbacks. This project developed a high-performance “green” anti-icer, based on grape skins and other agricultural wastes, that can minimize the harmful impacts of traditional chloride-based salts.

Freeze-Thaw Durability and Long-Term Performance Evaluation of Shotcrete in Cold Regions

In recent years, some states have replaced cast-in-place (CIP) concrete with shotcrete for structural earth retaining components such as fascia walls. Shotcrete also has the potential to be a solution for traditional reinforced concrete retaining walls—if it shows economic benefits and good long-term performance. This study’s aim was to evaluate the freeze-thaw durability of shotcrete in cold regions and to develop better ways to predict its long-term performance.

Environmentally Friendly Pervious Concrete for Treating Deicer-Laden Stormwater (Phase II)

Pervious concrete holds great potential to mitigate the effects of deicers in stormwater runoff in cold regions and to support environmental conservation. This study provided a better understanding of the freeze/thaw and salt scaling resistance of pervious concrete modified with fly ash, with or without graphene oxide.

Washington State Transportation Center