Publications

Summary:
This paper presents a systematic methodology for identifying and ranking bottlenecks using probe data collected by commercial GPS fleet management devices. This methodology is based on the hypotheses that truck speed distributions can be represented by either a unimodal or bimodal probability density function, and it proposes a new reliability measure for evaluating roadway performance.

Summary:
The ability to fully understand and accurately characterize freight vehicle route choices is important in helping to inform regional and state decisions. This project recommends improvements to WSDOT’s Statewide Freight GIS Network Model to more accurately characterize freight vehicle route choice. This capability, when combined with regional and sub-national commodity flow data, will be a key attribute of an effective statewide freight modeling system.

Summary:
The effective and efficient movement of freight is essential to the economic well-being of our country but freight transport also adversely impacts our society by contributing to a large number of crashes, including those resulting in injuries and fatalities.

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:
This paper compares the CO2 emissions from the use of personal vehicles to shared-use vehicles for grocery shopping in Seattle, Washington. The research builds on existing literature by considering the importance of modeling the logistical details of routing and scheduling, and by comparing the results of an American case study to existing European case studies.

Summary:
The adoption of defensible performance measures and establishment of proven results has become a necessity of many state Transportation Departments. A major factor in demonstrating results is the impact a transportation infrastructure improvement project has on the region’s economic climate.

Summary:
Onboard monitoring systems (OBMSs) can be used in commercial vehicle operations to monitor driving behavior, to enhance safety. Although improved safety produces an economic benefit to carriers, understanding how this benefit compares with the cost of the system is an important factor for carrier acceptance. In addition to the safety benefits provided by the use of OBMSs, operational improvements may have economic benefits.

Summary:
This paper describes the development of a systematic methodology for identifying and ranking bottlenecks using probe data collected by commercial global positioning system fleet management devices mounted on trucks. These data are processed in a geographic information system and assigned to a roadway network to provide performance measures for individual segments.

Summary:
Currently, knowledge of actual freight flows in the US is insufficient at a level of geographic resolution that permits corridor-level freight transportation analysis and planning. Commodity specific origins, destinations, and routes are typically estimated from four-step models or commodity flow models. At a sub-regional level, both of these families of models are built on important assumptions driven by the limited availability of data.

Summary:
In many regions throughout the world, freight models are used to aid infrastructure investment and policy decisions. Since freight is such an integral part of efficient supply chains, more realistic transportation models can be of greater assistance. Transportation models in general have been moving away from the traditional four-step model into activity-based and supply chain-based models. Personal transportation models take into consideration household demographics and why families travel.

Summary:
This study reviews the impact of public transit network layout (TNL) on resident mode choice. The review of TNL as a factor uses variables divided into three groups: a variable set without considering the TNL, one considering TNL from the zone level, and one considering TNL from the individual level. Using Baoding’s travel survey data, a Multinomial Logit (MNL) model is used, and the parameter estimation result shows that TNL has significant effect on resident mode choice. Based on parameter...

Summary:
Future reauthorizations of the federal transportation bill will require a comprehensive and quantitative analysis of the freight benefits of proposed freight system projects.

Summary:
This article considers the effectiveness of a truck appointment system in improving yard efficiency in a container terminal. This research uses the truck appointment information obtained from an appointment system to improve import container retrieval operation and reduce container rehandles by adopting an advanced container location assignment algorithm. By reducing container rehandles, the terminal could improve yard crane productivity and reduce truck transaction time.

Summary:
This study examines civil engineering students’ perceptions of freight transportation and its impacts on the environment and society.

Summary:
This paper proposes a method for calculating both the direct freight benefits and the larger economic impacts of transportation projects. The identified direct freight benefits included in the methodology are travel time savings, operating cost savings, and environmental impacts. These are estimated using regional travel demand models (TDM) and additional factors. Economic impacts are estimated using a regional Computable General Equilibrium (CGE) model.