Engineering Commons^™

A Conceptual Framework For Understanding Latent Demand: Accounting For Unrealized Activities And Travel, Kelly Clifton

PSU Transportation Seminars

Latent demand—the activities and travel that are desired but unrealized because of constraints—have been historically examined from the standpoint of understanding the impacts of proposed capacity or service improvements on travel demand.

Drawing on work from a variety of theoretical perspectives, this paper presents a broader conceptual view of latent demand that provides a useful framework for researching and understanding these unmet needs. This is important from an equity standpoint, as it provides insights into to questions of transport disadvantage, social exclusion and poverty.

The framework presented here is theoretical in nature and untested empirically. This study aims to promote …

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

PSU Transportation Seminars

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 is to rely …

Addressing Data Challenges For Bicycle Crash Analysis, Eleni Christofa

PSU Transportation Seminars

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 exposure as …

Big Data And The Future Of Travel Modeling, Greg Macfarlane

PSU Transportation Seminars

New technologies such as smart phones and web applications constantly collect data on individuals' trip-making and travel patterns. Efforts at using these "Big data" products, to date, have focused on using them to expand or inform traditional travel demand modeling frameworks; however, it is worth considering if a new framework built to maximize the strengths of big data would be more useful to policy makers and planners.

In this presentation Greg Macfarlane will present a discussion on elements of travel models that could quickly benefit from big data and concurrent machine learning techniques, and results from a preliminary application of …

Exploring The Positive Utility Of Travel And Mode Choice, Patrick Allen Singleton

PSU Transportation Seminars

Why do people travel? We traditionally assume traveling is a means to an end, travel demand is derived (from the demand for activities), and travel time is to be minimized. Recently, scholars have questioned these axioms, noting that some people may like to travel, use travel time productively, enjoy the experience of traveling, or travel for non-utilitarian reasons. The idea that travel can provide benefits and may be motivated by factors beyond reaching activity destinations is known as “the positive utility of travel” or PUT.

This study presents a conceptual and empirical look at the positive utility of travel and …

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 play …

Using Fuzzy Cognitive Maps To Model Policy Issues In The Face Of Uncertainty And Limited Data, Brian Gregor

PSU Transportation Seminars

Planners and policymakers are often faced with the need to make decisions about issues for which there is uncertainty and limited data. For example, transportation planners are now faced with the prospect that new transportation technologies such as autonomous vehicles could greatly alter future transportation system needs. Decisions about these types of issues are difficult to reason about and consequently are likely to be ignored or made on the basis of simplistic logic. Although modeling could be helpful, especially for issues involving complex systems, it is rarely used because models usually require large amounts of data and and handle uncertainty …

Current Efforts To Make Bike Share More Equitable: A Survey Of System Owners And Operators, Steven Howland

PSU Transportation Seminars

The number of public bike share systems has been increasing rapidly across the United States over the past five to ten years. To date most academic research around bike share in the U.S. has focused on the logistics of planning and operationalizing successful systems. Investigations of system users and impacts on the local community are less common, and studies focused on efforts to engage underserved communities in bike share are rarer still. This paper utilizes a survey of representatives from 55 U.S. bike share systems to better understand and document current approaches toward serving low income and minority populations. The …

Estimating Reliability Indices And Confidence Intervals For Transit And Traffic At The Corridor Level, Travis B. Glick

PSU Transportation Seminars

As congestion worsens, the importance of rigorous methodologies to estimate travel-time reliability increases. Exploiting fine-granularity transit GPS data, this research proposes a novel method to estimate travel-time percentiles and confidence intervals. Novel transit reliability measures based on travel-time percentiles are proposed to identify and rank low-performance hotspots; the proposed reliability measures can be utilized to distinguish peak-hour low performance from whole-day low performance. As a case study, the methodology is applied to a bus transit corridor in Portland, Oregon. Time-space speed profiles, heatmaps, and visualizations are employed to highlight sections and intersections with high travel-time variability and transit low performance. …

Webinar: Improving Walkability At Signalized Intersections With Signal Control Strategies, Edward J. Smaglik, Sirisha Murthy Kothuri

TREC Webinar Series

The goal of signal timing at an intersection should be to maximize efficiency for all users. In many jurisdictions, however, traffic signals are timed mostly with the goal of reducing vehicular delay.

Other road users, such as pedestrians, deserve similar focus. In legacy transportation systems, pedestrians experience delays much in excess of those that would be deemed acceptable for a motor vehicle at the same location.

Excessive delay can lead to pedestrian frustration, non-compliance and ultimately decreased safety.

In the North American context, implementation of strategies to address pedestrian service varies greatly across jurisdictions, and there has been limited research …

Avoiding Bus Bunching: From Theory To Practice, Ricardo Giesen

PSU Transportation Seminars

The problem of bus bunching in a high frequency service has been largely studied in the literature.

This phenomenon is produced by three main factors

(i) the variability in travel time between stops; (ii) variations in passenger demand; and (iii) drivers’ heterogeneity.

In order to tackle this phenomenon a wide range of control strategies have been proposed, however, none of them had been successfully implemented on a large transit network with high frequency services.

In this talk, we present a control scheme based on a rolling horizon optimization problem that has been successfully implemented for real-time control of two high …

Webinar: State-Wide Pedestrian And Bicycle Miles Traveled: Can We Estimate It?, Krista Nordback

TREC Webinar Series

Heard of Vehicle Miles Traveled (VMT)? Wouldn’t it be great to know the corresponding value for walking and cycling?

This webinar discusses options for estimating the miles people walk and bicycle on the state-wide level, by investigating the practical considerations of trying to compute these values for one study state.

What strategies can be used, and what data sources do these require?

How do these strategies compare?

How do PMT/BMT estimates vary based on data?

Find out what researchers found and what obstacles they encountered when they tried to estimate bicycle and pedestrian miles traveled in the State of Washington.

Pricing And Reliability Enhancements In The San Diego Activity-Based Travel Model, Joel Freedman

PSU Transportation Seminars

The estimation of demand for priced highway lanes is becoming increasingly important to agencies seeking to improve mobility and find alternative revenue sources for the provision of transportation infrastructure.

However, many modeling tools fall short of what is required for robust estimates of demand with respect to toll and managed lanes in two key areas:

• The value-of-time is often aggregate and not consistently defined throughout the model system, and
• The reliability of transport infrastructure is rarely taken into account.

This presentation describes an effort which implemented recommendations of the Strategic Highway Research Program C04 and L03\L04 tracks on pricing and …

Webinar: Transit Signal Priority Evaluation And Performance Measures, Miguel Figliozzi

TREC Webinar Series

Transit signal priority (TSP) can reduce transit delay at signalized intersections by making phasing adjustments. TSP is a relatively inexpensive tool to provide faster and more reliable transit service. This webinar addresses TSP real-word performance measures as well as data integration and evaluation challenges. Results of the TSP evaluation in an arterial corridor in Portland, Oregon indicate that a timely and effective TSP system requires a high degree of sophistication, monitoring, and maintenance. TSP timing is crucial to reduce transit delay.

Key takeaways include: performance measures, methodology, analysis of early green and red extension pros and cons, novel real-world results.

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

PSU Transportation Seminars

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 …

Connected Vehicles And Rural Road Weather Management, Rhonda Young

PSU Transportation Seminars

Changing weather patterns and increases in extreme weather events has led to the deployment of more weather responsive traffic management strategies. As the transportation system moves towards a connected vehicle environment, questions arise as to how connected vehicle technology can support weather responsive systems. The presentation will discuss the use of connected vehicles in a rural environment as providers of mobile weather data. Two projects will be highlighted - a recently completed research project using passenger vehicle CAN-BUS data as weather surrogates, and the ongoing USDOT CV Pilot Deployment Project in Wyoming.

Measuring What We Value: Using Performance Measures To Achieve Goals, Chris Rall

PSU Transportation Seminars

Performance measures are commonly used in transportation planning, but how effectively are public agencies using them, and to what ends?

Metro, ODOT and many cities use performance measures to evaluate investment choices and monitor progress. Drawing from Transportation for America’s report Measuring What We Value, and some of the most cutting edge examples of performance-based planning around the nation, Chris' presentation will step back to consider what makes a performance-based planning approach effective at achieving an agency’s goals.

Webinar: Development Of A Pedestrian Demand Estimation Tool, Kelly Clifton

TREC Webinar Series

Why model pedestrians?

A new predictive tool for estimating pedestrian demand has potential applications for improving walkability. By forecasting the number, location and characteristics of walking trips, this tool allows for policy-sensitive mode shifts away from automobile travel.

There is growing support to improve the quality of the walking environment and make investments to promote pedestrian travel. Despite this interest and need, current forecasting tools, particularly regional travel demand models, often fall short. To address this gap, Oregon Metro and NITC researcher Kelly Clifton worked together to develop this pedestrian demand estimation tool which can allow planners to allocate infrastructure …

Webinar: Impacts Of Roadway And Traffic Characteristics On Air Pollution Risks For Bicyclists, Alexander Y. Bigazzi

TREC Webinar Series

Active travel such as walking and bicycling can lead to health benefits through an increase in physical activity. At the same time, more active travelers breath more and so can experience high pollution inhalation rates during travel. This webinar will review the state of knowledge about how roadway and traffic characteristics impact air pollution risks for bicyclists, including the latest PSU research quantifying bicyclists' uptake of traffic-related air pollution using on-road measurements in Portland. The PSU research team including Alex Bigazzi, Jim Pankow, and Miguel Figliozzi quantified bicyclist exposure concentrations on different types of roadways, respiration responses to exertion level, …

Webinar: Exploring Pedestrian Responsive Traffic Signal Timing Strategies In Urban Areas, Sirisha Murthy Kothuri

TREC Webinar Series

The role of walking in the development of healthy, livable communities is being increasingly recognized. In urban areas, intersections are often viewed as a deterrent to walking, as their operation primarily favors automobiles, leading to large and unnecessary delays for pedestrians. There is currently very limited research on accommodating and/or prioritizing pedestrians at signalized intersections in the North American context. Pedestrians are often considered as a deterrent to efficient vehicular traffic flow and therefore active efforts to include them in operational decisions at intersections have been lagging. This research aims to fill that gap by understanding factors that influence pedestrian …