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Introduction
Skills and Expertise
Publications
Publications (65)
As part of a cooperative agreement with FTA, the Tri-County Metropolitan Transportation District of Oregon (TriMet) in Portland, Oregon, conducted a demonstration test of three commercially available systems to warn pedestrians of turning transit buses. Forty-five buses were equipped with the warning systems for turning (15 buses with each of the t...
Urban form affects community development, livability, sustainability, and traffic safety. Urban planners have long assumed a relationship between urban form and traffic safety. That relationship favors designs with fewer through streets because such designs are believed to improve safety. An empirical study to explore this assumed relationship used...
This paper examines extraboard operations at TriMet, the transit provider for the Portland, Oregon, metropolitan area. The extraboard consists of a pool of operators who fill open work resulting from absences and other causes. Drawing on 7 years of daily operations data, the paper examines first the general performance of the extraboard in filling...
This paper presents an analysis of access mode choice by riders of one of the first U.S. suburb-to-suburb commuter railroads, the Westside Express (WES), in the Portland, Oregon metropolitan area. The study uses on-board survey data collected by the region’s transit agency, Tri-Met, during WES’s first year of operation. The data include observed ac...
This paper analyzes factors contributing to bus operations safety incidents at TriMet, the transit provider for the Portland Oregon metropolitan region.
The analysis focuses on 4,631 collision and non-collision incidents that occurred between 2006 and 2009. Empirical analysis of these incidents draws on a wide array of operator-level data recovered...
Factors that contribute to short-duration (1 to 3 days) unscheduled absences of operators at the Tri-County Metropolitan Transportation District of Oregon (TriMet), the transit provider for the Portland, Oregon, metropolitan region, are analyzed. The analysis draws on a wide array of operator-specific information recovered by the technologies of tr...
A ranking of 33 urban studies and urban affairs programs in the US was developed from peer ratings obtained in a program survey and from citation activity reported in the Social Sciences Citation Index over the 1986–1989 period. A breakdown of citations by broadly defined subject areas is presented. The survey revealed a difference between Ph.D. an...
Historically, schedulers and operations management personnel have made decisions with limited information about various states
of the transit system. The present study highlights innovative uses of data collected via automatic vehicle location and automatic
passenger count technologies in the areas of scheduling and operations management at TriMet,...
This paper examines the impacts of JRS articles in the areas of theory, methods and empirical analysis, as represented by subsequent citations reported in the Social Sciences Citation Index. A model relating the mix of theoretical, methodological and empirical research published in the JRS to subsequent citations is estimated. The time distribution...
TRB’s Transit Cooperative Research Program (TCRP) Report 113: Using Archived AVL-APC Data to Improve Transit Performance and Management explores the effective collection and use of archived automatic vehicle location (AVL) and automatic passenger counter (APC) data to improve the performance and management of transit systems. Spreadsheet files are...
This research addressed changes in passenger activity and operating performance after implementation of a bus stop consolidation project at TriMet, the regional transit provider for the Portland, Oregon, metropolitan area. Extensive use was made of archived bus operations and passenger activity data from TriMet's automated Bus Dispatch System. Chan...
This research addressed changes in passenger activity and operating performance after implementation of a bus stop consolidation project at TriMet, the regional transit provider for the Portland, Oregon, metropolitan area. Extensive use was made of archived bus operations and passenger activity data from TriMet’s automated Bus Dispatch System. Chan...
ABSTRACT This paper presents findings from an evaluation of the accuracy of automatic passenger counters (APCs) on TriMet’s light rail vehicles. APC boarding and alighting counts were compared to manually recorded counts. Overall, the APCs tended to under-count boardings and over-count alighting alightings. Thus, correction factors will be needed i...
Findings are presented on changes in bus running times, on-time performance, and excess passenger wait times following implementation of transit signal priority (TSP) in select bus corridors in the Portland metropolitan region. Analysis of the effectiveness of TSP is often undertaken by using simulation techniques or empirical studies that are lim...
Performance measures for a multimodal corridor are developed and implemented in the Portland, Oregon Interstate 5 test bed. With the implementation of Intelligent Transportation Systems (ITS), extensive disaggregate transportation data sets are now available and can be used as the basis for generating transportation performance measures along on th...
This paper presents findings from an evaluation of the accuracy of automatic passenger counters (APCs) on the Tri-County Metropolitan Transportation District of Oregon’s (TriMet’s) light rail vehicles. APC boarding and alighting counts were compared with manually recorded counts. Overall, the APCs tended to undercount boardings and overcount alight...
Although automatic passenger counters (APCs) have been used for many years, significant obstacles have hindered their becoming a mainstream source of data for monitoring ridership and peak load, estimating passenger miles, and other measures of passenger use important for transit management. The key to APC usefulness is the automatic, routine conve...
Abstract This paper analyzes changes in passenger passenger activity and operating performance following implementation of a bus stop consolidation project at TriMet, the regional transit provider for the Portland, Oregon metropolitan area. The study makes extensive use of archived bus operations and passenger activity data from TriMet’s automated...
This paper presents findings from an evaluation of the accuracy of automatic passenger counters (APCs) on the Tri-County Metropolitan Transportation District of Oregon's (TriMet's) light rail vehicles. APC boarding and alighting counts were compared with manually recorded counts. Overall, the APCs tended to undercount boardings and overcount alight...
Although automatic passenger counters (APCs) have been used for many years, significant obstacles have hindered their becoming a mainstream source of data for monitoring ridership and peak load, estimating passenger miles, and other measures of passenger use important for transit management. The key to APC usefulness is the automatic, routine conve...
Findings are presented on changes in bus running times, on-time performance, and excess passenger wait times following implementation of transit signal priority (TSP) in select bus corridors in the Portland metropolitan region. Analysis of the effectiveness of TSP is often undertaken by using simulation techniques or empirical studies that are limi...
Bus dwell time data collection typically involves labor-intensive ride checks. This paper reports an analysis of bus dwell times that use archived automatic vehicle location (AVL)/automatic passenger counter (APC) data reported at the level of individual bus stops. The archived data provide a large number of observations that serve to better unders...
Automatic vehicle location (AVL) and other automated data collection systems can provide a rich and extensive database that can be analyzed to improve transit management and performance. In the past, many such systems have failed to provide a good data archive, while others have had success. Through the use of an extensive survey and in-depth case...
In this paper we empirically analyze the relationship between transit service headway deviations and passenger loads, using archived data from Tri-Met's automatic vehicle location and automatic passenger counter systems. The analysis employs two-stage least squares estimation to account for the simultaneous relationship between headway deviations a...
This paper estimates the relationship between crash activity and roadway design attributes on the Oregon state highway system. Crash models are estimated from roadway segments distinguished by functional classification and location. A number of design attributes were found to be related to crash activity in the various models, including number of l...
Findings from a study assessing the accuracy and precision of automatic passenger counter (APC) technology at Tri-County Metropolitan Transportation District of Oregon (Tri-Met) are presented. Video surveillance cameras, rather than ride checkers, were used to establish reference values for determining APC accuracy and precision. Analysis of data c...
In this paper, archived Automatic Vehicle Location and Automatic Passenger Counter data are used to evaluate actual bus running time variation in relation to scheduled service for Tri-Met, the transit provider for the Portland, Oregon metropolitan area. Given observed variation in running times, scheduled recovery times are found to be generally (t...
The authors gratefully acknowledge support provided by Tri-Met and the USDOT University Transportation Centers Program, Region X (TransNow). In addition, a number of individuals at Tri-Met made important contributions to the operations control experiment reported herein. They include Wes Burns, who served as the dispatcher dedicated to tracking sub...
This paper presents findings on initial changes in service reliability following Tri-Met's deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. Changes in on-time performance, headway variation, run time variation, and run times were determined with respect to predeployment levels....
Faculty rank is often included as an explanatory variable in academic salary models. Because there is reason to believe that this results in specification bias, rank effects should be estimated endogenously in salary models. A salary model in which faculty rank is endogenous is estimated in this article and the results are compared with those obtai...
In this paper we estimate the relationship between road capacity and vehicle miles of travel (VMT) from a sample of 12,000 respondents from 48 urban areas in the 1995 Nationwide Personal Transportation Survey (NPTS). Our approach seeks to account for the effects of residential location, employment location, and commute mode choice in estimating the...
Tri-Met, the transit provider in Portland, Oregon, is implementing a new computer-aided bus dispatching system that uses a satellite-based global positioning system to track vehicle location. It is expected that the new system will produce improvements in service reliability. Presented is a baseline analysis of service reliability on selected route...
This article looks at the connection between the regulation of parking by cities, transit service levels, and travel and parking behavior in the United States. Travel behavior information comes from the 1990 Nationwide Personal Transportation Survey (NPTS) and the Federal Urban Mass Transportation Administration's 1990 Section 15 Report. Data on th...
In this paper we present a route-level patronage model that incorporates transit demand, supply and inter-route effects in a simultaneous system. The model is estimated at the route-segment level by time of day and direction. The results show strong simultaneity among transit demand, supply and competing routes. Transit ridership is affected by the...
This paper looks at the connection between the regulation of parking by cities, transit service levels, and travel and parking behavior in the United States. Travel behavior information comes from the 1990 Nationwide Personal Transportation Survey (NPTS) and the Federal Urban Mass Transportation Administration's 1990 Section 15 Report. Data on the...
The effect of parking prices on mode choice for urban work travel is investigated, controlling for access to transit and residential and employment location. The analysis uses a nested multinomial logit model and is based on travel-activity data from the Portland, Oregon, metropolitan area. Parking prices are estimated to have a significant influen...
This paper tests the hypothesis that benefit spillovers from public higher educationproxied by out-niigration-led to lower higher education appropriations by state legislatures. A model addressing legislative appropriations, tuition and out-migration activity is developed and estimated. The results support the benefit spillover hypothesis, indicati...
This paper analyzes trip chaining, focusing on how households organize non-work travel. A trip chaining typology is developed using household survey data from Portland, Oregon. Households are organized according to demographic structure, allowing analysis of trip chaining differences among household types. A logit model of the propensity to link no...
This paper presents an empirical assessment of factors affecting on-time performance in Portland, Oregon's fixed route bus system. A multinomial logit model relating early, late and on-time bus arrivals to route, schedule, driver and operating characteristics is developed and estimated. The model results show that the probability of on-time failure...
Analysis of population patterns in the United States during the 1970s has shown a substantial redirection to non-metropolitan areas. A similar redirection to rural parts of metropolitan areas is occurring. This study examines population deconcentration at one locational scale—the urban fringe—using data from a sample of households taken from the An...
The jointness efficiency of large jurisdictions and the distributional efficiency of small jurisdictions present a dilemma in the organization of a governmental system. Working from the point of view that governments exist to provide services, the two types of efficiency are integrated through Lagrangian methodology. The result is an optimal provis...
This guidebook describes currently used intelligent transportation systems (ITS) and Transit ITS technologies that have the greatest promise for transit market research. It documents ITS and Transit ITS technologies currently in use, assesses their potential to provide market research data, and presents methods for collecting and analyzing these da...
Abstract This paper presents findings on initial changes in service reliability following Tri-Met’s deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. Changes in on-time performance, headway variation, run time variation, and run times were determined with respect to pre-deploymen...
This report will be of interest to transportation and urban planners and to local decisionmakers. The effectiveness of automobile parking strategies as a means of increasing transit ridership was analyzed. Eight strategies affecting the price and availability of parking and transit service levels were examined, alone and in combination, to assess t...
This project evaluates the cost-effectiveness of Tri-Met`s demand-responsive service in the Sunnyside area of Portland. Ridership and costs of demand-responsive service will be related to estimates of ridership and cost for fixed route service in that area. The latter estimates will be generated by GIS-based route demand model developed for Tri-Met...
The authors gratefully acknowledge support provided by Tri-Met, the Multnomah County Bridge Section, and the USDOT University Transportation Centers Program, Region X (TransNow). The contents of this paper reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessari...
Print reproduction from microfilm. Thesis (Ph. D.)--University of Iowa.
