Publications

Summary:
A factor that influences transit ridership but has not received much attention from researchers is weather. This paper examines the effects of weather on bus ridership in Pierce County, Washington, for the years 2006–2008. Separate ordinary least squares regression models were estimated for each season, as weather conditions may have different effects depending on the time of year. Four weather variables were considered: wind, temperature, rain, and snow.

Summary:
As awareness of the vulnerability of isolated regions to natural disasters grows, the demand for efficient evacuation plans is increasing. However, isolated areas, such as islands, often have characteristics that make conventional methods, such as evacuation by private vehicle, impractical to infeasible. Mathematical models are conventional tools for evacuation planning.

Summary:
This life cycle assessment case study puts the supply chain contribution of transportation to greenhouse gas emissions in context with other contributors using American wheat grain as a representative product. Multiple locations, species and routes to market are investigated.

Summary:
Between 1998 and 2005, employment in the U.S. warehousing industry grew at a compound annual growth rate of 22.23%, and the number of establishments increased at compound annual growth rate of 9.48%. Over this same period of time, the price for transportation fuels increased dramatically and became much more volatile. In this paper we examine the microeconomic and macroeconomic forces that have enabled such rapid growth in the warehousing industry.

Summary:
Most of a delivery driver’s time is spent outside the vehicle, walking the last 50 feet to reach the delivery customers while the vehicle is stationary. However, little is known about the walking component of delivery routes, while most models and algorithms used for scheduling and planning urban freight vehicles focus solely on the driving component. This study fills this research gap by providing an empirical analysis of the role of walking in last-mile deliveries.

Summary:
As one of the nation’s first zero-emissions last-mile delivery pilots, the Seattle Neighborhood Delivery Hub served as a testbed for innovative sustainable urban logistics strategies on the ground in Seattle’s dense Uptown neighborhood.

Summary:
Problem, research strategy, and findings The transportation sector is the largest contributor of greenhouse gas emissions in the United States. To articulate how cities may combat rising emissions, municipalities throughout the country have produced climate action and sustainability plans that outline strategies to reduce their carbon footprints from transportation.

Summary:
The violation of the International Regulations for Preventing Collisions at Sea (COLREGS) is a precursor to the majority of collisions. These violations may indicate a poor safety culture within shipping or they may indicate the failure of the COLREGS to capture the modern ordinary practice of seamen. The COLREGS are a mix of rules and regulations. Regulations are a form of explicit, externally applied control; while the text of a rule is ambiguous and requires observing the system it refers...

Summary:
Predicting the stay time of private cars has various applications in location-based services and traffic management. Due to the associated randomness and uncertainty, achieving the promising performance of stay time prediction is a challenge. We propose an RNN-based encoder model to solve this problem, which consists of three components, i.e., an encoder module, an exception module, and an MLP dropout.

Summary:
This study is sponsored by Amazon, Bellevue Transportation department, Challenge Seattle, King County Metro, Seattle Department of Transportation, Sound Transit, and Uber, with support from the Mobility Innovation Center at UW CoMotion. Population and extended economic growth in many Seattle neighborhoods are driving increased demand for private car travel along with transportation services such as ridehailing and on-demand delivery.

Summary:
This report discusses the travel costs associated with the closure of roads in the greater Centralia/Chehalis, Washington region due to 100-year flood conditions starting on the Chehalis River. The costs were computed for roadway closures on I-5, US 12, and SR 6, and are based on estimated road closure durations supplied by WSDOT. The computed costs are only those directly related to travel that would otherwise have occurred on the roads affected by the flooding closures.

Summary:
Efficient and reliable goods movement via our nation’s highway system is critical to the nation’s economy and quality of life. Truck mobility is one of the key performance measures for evaluating the conditions of goods movement and supporting freight planning. Truck GPS data can be useful in developing truck mobility measures and providing insights into freight planning.

Summary:
This article will explore the reliability of the port drayage network. Port drayage is an important component of the marine intermodal system and affects the efficiency of the intermodal supply chain. Sharing and utilizing drayage truck arrival information could improve both port drayage and port operational efficiency. In this article two reliability measures are used to evaluate how the travel time reliability changes with trip origins and across drayage networks.

Summary:
Quantifying the relationship between the number and types of truck trips generated by different land uses provides information useful for traffic demand analyses, forecasting models, and a general understanding of the factors that affect truck mobility. This project evaluated data collection methodologies for determining truck trip generation rates by studying a specific kind of establishment.