Engineering Commons^™

How Av Could Shape Our Cities - Research From The Netherlands, Gonçalo H. A. Correia

PSU Transportation Seminars

Automated driving has become a hot topic of research in different fields of science. Despite the great advancements in the vehicle technology itself, researchers are now concerned in figuring out what will be the impacts of these vehicles in life as we know it. These impacts can be rather broad from traffic safety to the economy. In this lecture, Goncalo will focus on the research that is being done at TU Delft, a leading university in automated vehicles’ (AVs) impacts research, focusing on urban areas and how mobility, and even the city itself, can change with fully-automated vehicles. Goncalo Correia …

Focusing On Equity In Regional Plans, Kristine M. Williams

TREC Project Briefs

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes.

Evaluating The Distributional Effects Of Regional Transportation Plans And Projects, Kristine Williams, Aaron Golub

TREC Final Reports

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes. Funded by the National Institute for Transportation and Communities, this research aims to provide additional guidance to MPOs on how to evaluate distributional equity in regional plans and projects. The report begins with an overview of federal requirements related to equity in transportation planning. We then synthesize contemporary methods for measuring transportation equity and the distributional effects of plans and projects from a review of the literature and MPO plans and studies. The report concludes with exploratory case studies of …

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 …

A Practitioner's Guide To Urban Trip Generation, Kristina Marie Currans

TREC Project Briefs

In 1976, the Institute of Transportation Engineers (ITE) compiled their first Handbook of guidelines for evaluating development-level transportation impacts. Decades later, these methods are still ubiquitously used across the US and Canada. Only recently, with the third edition of the ITE Trip Generation Handbook, have new data and approaches been adopted. In this study NITC researcher Kristina Currans takes aim at understanding issues inherent in the collection and application of ITE’s data and methods in various urban contexts. This technology transfer guide touches on the main findings from this work.

Issues In Trip Generation Methods For Transportation Impact Estimation Of Land Use Development: A Review And Discussion Of The State-Of-The-Art Approaches, Kristina Marie Currans

Civil and Environmental Engineering Faculty Publications and Presentations

As agencies develop more robust planning objectives for creating sustainable and livable communities, the research community has continued developing supportive tools and methods to provide more accurate and robust means for estimating transportation impacts for site-level development review. This paper is a review of the state-of-the-art trip generation methods for land use transportation impact estimation. First, it provides an overview of the more recent available and peer-reviewed estimation methods. Second, the authors offer a discussion of the successes of state-of-the-art approaches using common themes of research to identify corresponding consistency with theories of travel behavior and urban economics. These themes …

Accessibility, Income, And Person Trip Generation: Multilevel Model Of Activity At Food Retail Establishments In Portland, Oregon, Kristina Marie Currans, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

In the past decade, the methods for estimating multimodal transportation impacts of urban land use development have improved substantially. One assumption commonly made in these new methods is that overall person-trip rates at similarly-sized establishments of the same land use do not vary across a region. This is an assumption of convenience to permit the adjustment of ITE Trip Generation vehicle trip rates for use in different urban environments. However, this assumption is inconsistent with theories of urban economics, which recognize that businesses pay a premium to locate in areas with high levels of accessibility to attract more customers. In …

Comparing Mode Shares For Non-Residential Destinations In Urban And Suburban Environments, Tasnia Subrin

Student Research Symposium

To ensure facility for multimodal transportation is one of the most important concerns in today’s transportation sector, with initiatives being taken to make multimodal transportation popular. The built environment variables have a strong relationship with transportation mode choice, but whether that relationship holds true in urban and suburban neighborhoods in the same manner has not been considered. Using data for three non-residential land uses, this research explores whether the built environment variables in suburban areas influences mode share like it does in urban areas. We used survey data conducted at the establishments regarding respondents’ travel characteristics from a previous study, …

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 …

How To Estimate Pedestrian Demand, Kelly Clifton, Patrick Allen Singleton, Christopher D. Muhs, Robert J. Schneider

TREC Project Briefs

There is growing support to improve the quality of the walking environment and make investments to promote pedestrian travel. Such efforts often require analytical non-motorized planning tools to estimate levels of pedestrian demand that are sensitive to environmental and demographic factors at an appropriate scale. 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 a pedestrian demand estimation tool. For generations, planners have been using statistical models to forecast travel demand, but these models have traditionally been auto-centered. …

Development Of A Pedestrian Demand Estimation Tool, Kelly Clifton, Patrick Allen Singleton, Christopher D. Muhs, Robert J. Schneider

Civil and Environmental Engineering Faculty Publications and Presentations

Most research on walking behavior has focused on mode choice or walk-trip frequency. In contrast, this study is one of the first to analyze the destination choice behaviors of pedestrians. Using about 4,500 walk trips from a 2011 household travel survey in the Portland, OR, region, we estimated multinomial logit pedestrian destination choice models for six trip purposes. Independent variables included terms for impedance (walk-trip distance); size (employment by type, households); supportive pedestrian environments (parks, a pedestrian index of the environment variable called PIE); barriers to walking (terrain, industrial-type employment); and traveler characteristics. Unique to this study was the use …

Adjusting Ite’S Trip Generation Handbook For Urban Context, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs

Civil and Environmental Engineering Faculty Publications and Presentations

This study examines the ways in which urban context affects vehicle trip generation rates across three land uses. An intercept travel survey was administered at 78 establishments (high-turnover restaurants, convenience markets, and drinking places) in the Portland, Oregon, region during 2011. This approach was developed to adjust the Institute of Transportation Engineers (ITE) Trip Generation Handbook vehicle trip rates based on built environment characteristics where the establishments were located. A number of policy-relevant built environment measures were used to estimate a set of nine models predicting an adjustment to ITE trip rates. Each model was estimated as a single measure: …

Using Household Travel Surveys To Adjust Ite Trip Generation Rates, Kristina Marie Currans, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

The Institute of Transportation Engineers (ITE) Trip Generation Handbook has become the predominant method for estimating vehicle trips generated by development. The handbook is often criticized for its inability to account for multimodal behavior in urban contexts, often overestimating vehicle traffic. The purpose of this research is to develop and test a ready-to-use method for adjusting the ITE handbook vehicle trip generation estimates for urban context. This method was created using household travel surveys from Oregon, Washington, and Maryland, as well as nationally available built environment data. Three adjustments were estimated for eight general land-use categories, including a “pooled” category …

More Urban Form, Fewer Auto Trips, Kelly J. Clifton

TREC Project Briefs

Trip generation refers to the number of vehicle trips that are predicted to originate in a given zone. The Institute of Transportation Engineers (ITE) publishes standard trip generation rates for various land use types, but these rates are primarily measured in low-density suburban areas. There is national interest in building data that expands upon the existing ITE trip generation rates to include sites located in a multi-modal context.

In areas that have a more compact urban form, better access to transit and a greater mix of land uses, fewer vehicle trips may be generated there than ITE rates indicate. However, …

Contextual Influences On Trip Generation, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs

Civil and Environmental Engineering Faculty Publications and Presentations

There is national interest in building data that expands upon the existing Institute of Transportation Engineers (ITE) trip generation rates to include sites located in a multi-modal context. Current ITE rates represent travel behavior for development in single lots and uses, primarily measured in low-density suburban areas. Despite evidence that a more compact urban form, access to transit and a greater mix of uses generates fewer and shorter vehicle trips, local governments are often compelled to use current ITE trip generation rates to evaluate transportation impacts and calculate transportation system development charges (TSDCs). This is due to: a) the expense …