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Full-Text Articles in Engineering

Examining Bicycle And Motorized Vehicle Speeds And Their Relationships In The Context Of Urban Roadways, Jaclyn Sue Schaefer Dec 2020

Examining Bicycle And Motorized Vehicle Speeds And Their Relationships In The Context Of Urban Roadways, Jaclyn Sue Schaefer

Dissertations and Theses

This thesis presents a compilation of papers exploring passenger car and bicycle speeds through their interactions with each other and with urban roadway factors.

First, following a concern raised in part of the traffic literature that a large mode shift toward bicycling may cause travel time delays and potentially exacerbate congestion instead of alleviate it unless bicycle lanes are installed, an empirical study detailing how the presence of bicycles on urban roads without bicycle lanes may affect passenger car speeds is presented. Pneumatic tube data from six predominantly low speed, low volume roads in Portland, Oregon were utilized to identify ...


An Empirical Study Of The Impacts Of Bicycles On Passenger Car Speeds On Urban Roads Without Bicycle Lanes, Jaclyn S. Schaefer, Miguel Figliozzi, Avinash Unnikrishnan Jan 2020

An Empirical Study Of The Impacts Of Bicycles On Passenger Car Speeds On Urban Roads Without Bicycle Lanes, Jaclyn S. Schaefer, Miguel Figliozzi, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

Higher bicycle mode share has been suggested as part of a solution to reduce the burden of congestion in urban areas. As strategies to promote bicycling are implemented, concerns have been raised by some road users and stakeholders citing simulation based traffic studies that indicate that an increase in the bicycle mode share generates major travel time delays via reduced vehicle speeds unless bicycle lanes are provided. The current research investigates the effects bicycles may have on motorized vehicle speeds on a variety of lower speed and volume urban roads without bicycle lanes. A detailed comparative analysis of passenger car ...


Travel Behaviors Of Persons With Intellectual And Developmental Disabilities, Joseph C. Totten Jun 2019

Travel Behaviors Of Persons With Intellectual And Developmental Disabilities, Joseph C. Totten

Civil and Environmental Engineering Master's Project Reports

People with intellectual and developmental disabilities live different lives than the general population. Often prohibited from driving, persons with intellectual disabilities cite transportation as top concern, limiting their independence and freedom to live, work or recreate where and when they choose. Improving services for persons with developmental disabilities requires that engineers and planners understand how persons with intellectual disabilities travel, and what types of transportation are available to them. This report hopes to identify the availability of transportation options to persons with developmental disabilities such that planners, engineers and advocates can determine how altering the transportation system might affect persons ...


Modeling The Impact Of Traffic Conditions And Bicycle Facilities On Cyclists' On-Road Stress Levels, Àlvaro Caviedes, Miguel A. Figliozzi Oct 2018

Modeling The Impact Of Traffic Conditions And Bicycle Facilities On Cyclists' On-Road Stress Levels, Àlvaro Caviedes, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Past research efforts have shown that cyclists’ safety, stress, and comfort levels greatly affect the routes chosen by cyclists and cycling frequency. Some researchers have tried to categorize cyclists’ levels of traffic stress utilizing data that can be directly measured in the field, such as the number of motorized travel lanes, motorized vehicle travel speeds, and type of bicycle infrastructure. This research effort presents a novel approach: real-world, on-road measurements of physiological stress as cyclists travel across different types of bicycle facilities at peak and off-peak traffic times. By matching videos with stressful events, it was possible to observe the ...


Transportation Impacts Of Affordable Housing: Informing Development Review With Travel Behavior Analysis, Amanda Howell Apr 2018

Transportation Impacts Of Affordable Housing: Informing Development Review With Travel Behavior Analysis, Amanda Howell

TREC Friday Seminar Series

Planning for affordable housing is challenged by development policies that often do not differentiate between the travel patterns of residents of market-rate housing and those living in affordable units. The development review process generally requires an evaluation of the anticipated additional transportation demand that new development places on the system and an assessment of fees or improvements to mitigate these impacts.

However, industry standard guidelines for assessment of travel demand outlined within the Institute of Transportation Engineers (ITE) Trip Generation Handbook have been focused solely on vehicle trip rates for these traffic impact analyses. Given the public goals of providing ...


Exploring The Determinants Of Vulnerable Road Users’ Crash Severity In State Roads, Álvaro Caviedes Jan 2018

Exploring The Determinants Of Vulnerable Road Users’ Crash Severity In State Roads, Álvaro Caviedes

TREC Friday Seminar Series

Part of the Student Presentations from TRB

Pedestrians and bicyclists are the most vulnerable road users and suffer the most severe consequences when crashes take place. An extensive literature is available for crash severity in terms of driver safety, but fewer studies have explored non-motorized users’ crash severity. Furthermore, most research efforts have examined pedestrian and bicyclist crash severity in urban areas. This study focuses on state roads (mostly outside major urban areas) and aims to identify contributing risk factors of fatal and severe crashes involving pedestrians and bicyclists in state roads. The results seem to suggest that besides improvements ...


Transportation Impacts Of Affordable Housing: Informing Development Review With Travel Behavior Analysis, Amanda Howell, Kristina Marie Currans, Steven R. Gehrke, Gregory Norton, Kelly J. Clifton Jan 2018

Transportation Impacts Of Affordable Housing: Informing Development Review With Travel Behavior Analysis, Amanda Howell, Kristina Marie Currans, Steven R. Gehrke, Gregory Norton, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Planning for affordable housing is challenged by development policies that assess transportation impacts based on methodologies that often do not distinguish between the travel patterns of residents of market-rate housing and those living in affordable units. Given the public goals of providing affordable housing in areas with good accessibility and transportation options, there is a need to reduce unnecessary costs imposed by the potential overestimation of automobile travel and its associated impacts. Thus, the primary objective of this paper is to examine and quantify the influences of urban characteristics, residential housing type, and income on metrics commonly used to assess ...


Advisory Bike Lanes In North America, Michael Williams Oct 2017

Advisory Bike Lanes In North America, Michael Williams

TREC Friday Seminar Series

Despite being used successfully for decades in Europe, Advisory Bike Lanes are an emerging facility type in North America and can be an effective tool for communities wishing to provide bicycle lanes on streets that are otherwise too narrow to accommodate them. This talk will introduce the concept and operation of advisory bike lanes and look at some lessons learned from the early installations of this facility in the U.S. and Canada.


Getting To Know The Data: Understanding Assumptions, Sensitivities, Uncertainty, And Being "Conservative" While Using Ite's Trip Generation Data In The Land Development Process, Kristina Marie Currans Apr 2017

Getting To Know The Data: Understanding Assumptions, Sensitivities, Uncertainty, And Being "Conservative" While Using Ite's Trip Generation Data In The Land Development Process, Kristina Marie Currans

TREC Friday Seminar Series

Many agencies rely on trip generation estimates to evaluate the transportation impacts of land development in urban and suburban areas alike. Over the past decade, substantial attention has been paid to one national set of guidelines—the Institute of Transportation Engineers (ITE) Trip Generation Handbook (2014) and corresponding Manual (2012)—focusing in particular to improve the use of these data and supplementary methods for urban contexts.

The purpose of this study is to explore the typical data provided in the Handbook, within the context of these new improved state-of-the-art methods. As ITE’s describes, “an example of poor professional judgment ...


Addressing Data Challenges For Bicycle Crash Analysis, Eleni Christofa Mar 2017

Addressing Data Challenges For Bicycle Crash Analysis, Eleni Christofa

TREC Friday Seminar Series

Although an increasing number of separated bicycle facilities have been appearing across the US over the last few years, the majority of bicyclists are still traveling on roadways shared with motorized vehicles.

As a result, bicycles are essentially double exposed to safety risk, due to their interactions with both motorized vehicles and other bicycles. In addition to this double exposure, data challenges–such as a lack of continuous counts and bicycle crash data—complicate the assessment of bicycle safety further.

This research presents a bicycle crash analysis framework for estimating bicycle crash rates accounting for both bicycle and motorized vehicle ...


Land Use Mix And Pedestrian Travel Behavior: Advancements In Conceptualization And Measurement, Steven Robert Gehrke Mar 2017

Land Use Mix And Pedestrian Travel Behavior: Advancements In Conceptualization And Measurement, Steven Robert Gehrke

Dissertations and Theses

Smart growth policies have often emphasized the importance of land use mix as an intervention beholding of lasting urban planning and public health benefits. Past transportation-land use research has identified potential efficiency gains achieved by mixed-use neighborhoods and the subsequent shortening of trip lengths; whereas, public health research has accredited increased land use mixing as an effective policy for facilitating greater physical activity. However, despite the celebrated transportation, land use, and health benefits of improved land use mixing and the extent of topical attention, no consensus has been reached regarding the conceptualization and measurement of this key smart growth principle ...


Webinar: Integrating Explicit And Implicit Methods In Travel Behavior Research: A Study Of Driver Attitudes And Bias, Tara Goddard Feb 2017

Webinar: Integrating Explicit And Implicit Methods In Travel Behavior Research: A Study Of Driver Attitudes And Bias, Tara Goddard

TREC Webinar Series

Car crashes are still a leading cause of death in the United States, with vulnerable road users like bicyclists and pedestrians being injured or killed at rates that outpace their mode share.

Planners, engineers, and advocates are increasingly adopting Vision Zero and Tactical Urbanism approaches and trying to better understand the underlying causes of dangerous roadway interactions. However, existing research into crash causation has focused on instrumental factors (e.g. intersection type, vehicle speed) while little research has probed the role of attitudes or socio-cognitive mechanisms in interactions between roadway users.

Social psychology suggests that attitudes and social cognitions can ...


Pursuing Vision Zero In Seattle – Results Of A Systemic Safety Analysis, Rebecca Sanders Jun 2016

Pursuing Vision Zero In Seattle – Results Of A Systemic Safety Analysis, Rebecca Sanders

TREC Friday Seminar Series

Many cities are considering pursuing Vision Zero to eliminate traffic deaths, but may not know how to move beyond addressing past crash locations toward preventing future crashes. Systemic analysis, which looks at crash patterns to determine common characteristics associated with various types of crashes, shows promise in helping cities to identify problematic locations and treatments in the hopes of preventing future crashes.

This presentation will share results from part of Seattle’s Vision Zero effort – a multi-phased analysis of pedestrian and bicycle crash data aiming to help the City understand both where crashes have occurred and where they are most ...


Utilizing High Resolution Bus Gps Data To Visualize And Identify Congestion Hot-Spots In Urban, Nicholas B. Stoll, Travis B. Glick, Miguel Figliozzi Jan 2016

Utilizing High Resolution Bus Gps Data To Visualize And Identify Congestion Hot-Spots In Urban, Nicholas B. Stoll, Travis B. Glick, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Congestion and travel delay on urban roadways can influence the roadways’ operating costs and service attractiveness. This research used high-resolution bus data to examine sources of delay on urban arterials. A set of tools was created to help visualize trends in bus behavior and movement; these tools allowed larger traffic trends to be visualized along urban corridors and streets. With buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. Speed plots were used to discover trends and travel patterns with only a ...


Integrating Freight Into Livable Communities, Kristine M. Williams, Alexandria Carroll Dec 2015

Integrating Freight Into Livable Communities, Kristine M. Williams, Alexandria Carroll

TREC Final Reports

Where livability is a goal of the planning process, freight runs the risk of not being considered except as an afterthought or as something to be excluded. Yet, freight is an integral part of local economic development. Because economic prosperity is a key characteristic of livable communities, freight must be incorporated into the planning process. This study explores the relationship between freight and livability through a comprehensive literature review and case study research. The final report includes a menu of strategies and case study perspectives that highlight the importance of transportation and land use integration, interagency coordination, and context-sensitivity in ...


Evaluating The Use Of Crowdsourcing As A Data Collection Method For Bicycle Performance Measures And Identification Of Facility Improvement Needs, Miguel A. Figliozzi, Bryan Philip Blanc Aug 2015

Evaluating The Use Of Crowdsourcing As A Data Collection Method For Bicycle Performance Measures And Identification Of Facility Improvement Needs, Miguel A. Figliozzi, Bryan Philip Blanc

Civil and Environmental Engineering Faculty Publications and Presentations

This research developed a smartphone application called ORcycle to collect cyclists’ routes, users, and comfort levels. ORcycle combines GPS revealed route data collection with new questionnaires that try to elicit cyclists’ attitudes as well as comfort levels and factors that influence their perceived comfort and route choice. The new questionnaires were developed to better understand how cyclists’ comfort levels are affected by route characteristics, route stressors, safety reports, cyclists’ demographics, and cyclists’ cycling attitude. Preliminary results show that many trip characteristics, route choice factors, route stressors and demographic variables are correlated with comfort levels. ORcycle is the first statewide deployment ...


Workshop Synthesis: Built Environment And Contextual Variables, Kelly Clifton, Pascal Perez Jan 2015

Workshop Synthesis: Built Environment And Contextual Variables, Kelly Clifton, Pascal Perez

Civil and Environmental Engineering Faculty Publications and Presentations

This two-day workshop focused on the important issue of how to define, convey and understand the built environment context as it relates to transport decisions. The field has grown tremendously over the last few decades, fueled in part by the increasing availability of archived spatial data about the environment and geo-referencing activity and travel patterns. But there are persistent issues particularly with inconsistencies in data format or availability across locations that hamper efforts to advance our understanding across regions. Further, there are new challenges in how we communicate context to survey respondents, particularly in stated preference surveys. Much of the ...


Transit Bus Fleet Age And Replacement Type Optimization, Miguel A. Figliozzi, Wei Feng, Jesse Boudart Sep 2013

Transit Bus Fleet Age And Replacement Type Optimization, Miguel A. Figliozzi, Wei Feng, Jesse Boudart

Civil and Environmental Engineering Faculty Publications and Presentations

Due to recent budget and fiscal constraints, it is ever more imperative for transit agencies to manage their fleets in an optimal way. Fleet data have consistently shown that bus operational and maintenance (O&M) per-mile costs increase as buses age. From a purely economic perspective, there is a cost tradeoff between the lower O&M costs of newer fleets and their higher initial capital costs. This tradeoff has a significant impact on the optimal timing of purchase and replacement decisions. Utilizing realistic cost data and an optimization modeling framework, we analyze (a) the impact of purchase timing decisions on fleet per-mile costs and (b) the key factors and variables affecting the optimization of transit diesel and hybrid bus fleets. Given uncertain and hard-to-forecast market variables, multiple scenarios are examined and sensitivity analyses are performed to study the impacts of key variables on optimal replacement policies and costs.

In terms of the impact of purchase timing decisions on fleet per-mile costs (a), results indicate that: 1) increases in diesel prices do not affect total bus fleet costs as much as increases in maintenance costs; 2) increases in maintenance costs and utilization per year reduce the optimal replacement age; 3) increases in utilization and fuel economy have a similar impact in terms of total fleet costs; and 4) bus purchase-price changes have a significant impact on the optimal replacement age.

In terms of the key factors and variables affecting the optimization of transit diesel and hybrid bus fleets (b), results indicate ...


Improving Vehicle Trip Generation Estimations For Urban Contexts: A Method Using Household Travel Surveys To Adjust Ite Trip Generation Rates, Kristina Marie Currans Jul 2013

Improving Vehicle Trip Generation Estimations For Urban Contexts: A Method Using Household Travel Surveys To Adjust Ite Trip Generation Rates, Kristina Marie Currans

Dissertations and Theses

The purpose of this research is to develop and test a widely available, ready-to-use method for adjusting the Institute of Transportation Engineers (ITE) Trip Generation Handbook vehicle trip generation estimates for urban context using regional household travel survey data. The ITE Handbook has become the predominant method for estimating vehicle trips generated by different land uses or establishment, providing a method for data collection and vehicle trip estimation based on the size of the development (e.g. gross square footage, number of employees, number of dwelling units). These estimates are used in traffic impact analysis to assess the amount of ...