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Transportation Engineering

Portland State University

Freight transportation -- Mathematical models

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Full-Text Articles in Engineering

Unobserved Heterogeneity And Spatial Correlation: Statistical And Econometric Analyses Of Heavy-Vehicle Hard Braking And Crash Frequency, Jason Anderson Oct 2018

Unobserved Heterogeneity And Spatial Correlation: Statistical And Econometric Analyses Of Heavy-Vehicle Hard Braking And Crash Frequency, Jason Anderson

PSU Transportation Seminars

In heavy-vehicles (a truck with a gross vehicle weight rating of greater than 10,000 pounds), a hard braking event is described as an event that prompts the vehicle’s “black box” to record an abrupt change in speed. More specifically, this occurs when the driver applies excess force to the vehicle’s brake. These hard braking events can then serve as a proxy for several factors, such as economic impacts, environmental impacts, and impacts on safety. In the context of the present study, being that approximately one-third of all heavy-vehicle-caused crashes in 2014 were attributed to faulty brakes, there is a need …


Behavior-Based Freight Modeling At Metro, Chris Johnson, Bud Reiff May 2017

Behavior-Based Freight Modeling At Metro, Chris Johnson, Bud Reiff

PSU Transportation Seminars

Chris Johnson and Bud Reiff will present on a behavior-based freight model being used at Oregon Metro. This model will replace Metro’s current truck model with a hybrid freight model that both represents multi-modal freight flows through elements of national and regional supply chains and simulates the movement of individual trucks and shipments on local networks. Model estimation and calibration will also require collection of behavioral data from shippers and receivers representing a wide range of industries, common and contract freight carriers, business that operate non-freight commercial vehicles, warehouse managers, and logistics agents.

Key project objectives:

  • Develop tools to enable …


The Relationship Between Vmt And Economic Activity, B. Starr Mcmullen, Nathan Eckstein Nov 2011

The Relationship Between Vmt And Economic Activity, B. Starr Mcmullen, Nathan Eckstein

TREC Final Reports

Vehicle miles traveled (VMT) in the U.S. have exhibited an upward trend over time similar to that observed for gross domestic product (GDP) and personal income (PI). While conventional wisdom suggests that economic growth leads to more driving and thus higher VMT, it is theoretically possible that the causation could also be the other way around. If causation is from VMT to GDP, then legislation such as the Federal Surface Transportation Policy and Planning Act of 2009’s directive to annually reduce national per capita VMT could potentially have an adverse impact on overall economic activity.

This study uses times series …


Freight Performance Measures: Approach Analysis, B. Starr Mcmullen, Christopher M. Monsere May 2010

Freight Performance Measures: Approach Analysis, B. Starr Mcmullen, Christopher M. Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

This report reviews the existing state of the art and also the state of the practice of freight performance measurement. Most performance measures at the state level have aimed at evaluating highway or transit infrastructure performance with an emphasis on passenger transportation. Freight performance measurement ultimately requires evaluation of performance of the entire freight transportation system, which includes highways, waterways, rail, air, and modal connections. This requires considerable expansion of thinking beyond the traditional focus of state Departments of Transportation (DOTs) on highway performance.

This project builds upon past and current work in the area of freight performance measurement and …