Ipek N. Sener

• Texas A&M University

This study analyzed data from a 2022 shared mobility survey to investigate the impact of gender on the potential improvements to on-demand transportation services, particularly shared-ride services such as ridesharing through transportation network companies (TNCs) and microtransit. Results revealed that male respondents were more inclined to opt f...

The US-Mexico border witnesses frequent cross-border travels for educational, recreational, healthcare, and work purposes, with millions of passenger and commercial vehicles crossing the international border each year. In 2020, pandemic-related travel restrictions were applied to non-US citizens at the US-Mexico border and reshaped cross-border tri...

Ridepooling service options introduced by transportation network companies (TNCs) and microtransit companies provide opportunities to increase shared-ride trips in vehicles, thereby improving congestion and environmental factors. This paper reviews the existing literature available on ridepooling and related services, specifically focusing on pooli...

The goal of this synthesis study is to provide relevant information about the current state of the practice in transit agencies to explore social media interaction. This report summarizes the reasons why agencies use social media, including public education and awareness, public engagement, quick updates, and crisis information; support of and infl...

During the past 20 years, social media has provided transit agencies with unparalleled opportunities to connect with their customers. The current synthesis topic will update TCRP Synthesis 99: Uses of Social Media in Public Transportation and will again explore the use of social media among transit agencies. The study will document innovative and e...

Utilizing GIS and location-based open data, this study examined the level of walkability for women in New York City. As highlighted through a thematic literature review, women experience the city differently than men, since they are more concerned with security issues related to aggression and harassment, as a major inhibitor of mobility in public...

Introduction Automated vehicle (AV) technologies are one of the most highly disruptive transportation technologies that have the potential to transform the existing transportation systems and the associated impacts on public health and health equity. There have been numerous attempts to recognize and frame the consequences of AVs on public health;...

This study contributes to research and practice by demonstrating the use of a composite measure, a bikeability index, to facilitate the use of and improve the performance of direct demand models for bicycle traffic, especially when only limited observation is available. The city of Austin was selected as a case study to develop the model using bicy...

This study examines the impacts of a community's transportation system on the quality of life provided to its residents. Other key livability factors are also identified, and their impacts on community quality of life are estimated. These livability indicators are categorized into four main dimensions: social, physical/climate, functional, and safe...

Despite evidence showing the spatial nonstationarity of the determinants of bike activity, very few studies have addressed the phenomena, probably due to the limited sample size of the traditional count data. To address this gap, this study demonstrated the applicability of Strava bike activity data by developing a geographically weighted Poisson r...

Reducing nonmotorized crashes requires a profound understanding of the causes and consequences of the crashes at the facility level. Generally, existing literature on bicyclists and pedestrian crash models suffers from two distinct problems: lack of exposure/volume data and inadequacy in capturing potential correlations across various crash aspects...

Monitoring bicycle trips is no longer limited to traditional sources, such as travel surveys and counts. Strava, a popular fitness tracker, continuously collects human movement trajectories, and its commercial data service, Strava Metro, has enriched bicycle research opportunities over the last five years. Accrued knowledge from colleagues who have...

The main premise of this chapter is that researchers, policy makers, and industry can learn a lot about the future adoption (and impact) of fully automated, self-driving vehicles by examining consumer acceptance, understanding, and trust of lower levels of automation (SAE Level 1 and Level 2). These are the levels of vehicle technology that exist o...

Growing attention on the benefits of non-motorized travel has increased the demand for accurate and timely pedestrian and bicycle travel data. Advancements in technologies and the proliferation of smartphones have created new data sources that can help eliminate limitations related to small sample size and infrequent updates due to limited resource...

A Bayesian Spatial Poisson-Lognormal Model to Examine Pedestrian Crash Severity at Signalized Intersections in Austin

Using data from the Houston Travel-Related Activity in Neighborhoods (TRAIN) study, this study examined how various factors affect whether individuals intend to use newly opened light-rail transit (LRT) lines in Houston. The Houston TRAIN study is a natural experiment on the effect of new LRT lines on both transit use and physical activity. A mixed...

Encouraging the use of nonmotorized modes of transportation is a goal at the intersection of public health, environment, and transportation, given active transportation’s numerous benefits to individuals and communities. However, increased use of nonmotorized modes can also bring increased pedestrian–vehicle and bicycle–vehicle crashes. About 4,000...

The advent of automated vehicles could be transformative to the existing transportation system; however, the ways in which changes could happen are uncertain. This research was aimed at contributing to the literature of acceptance of self-driving vehicles and the role of ride-hailing in this decision-making process. An online survey was implemented...

Over the last decade, demand for active transportation modes such as walking and bicycling has increased. While it is desirable to provide high levels of safety for these eco-friendly modes of travel, unfortunately, the overall percentage of pedestrian and bicycle fatalities increased from 13% to 18% of total road-related fatalities in the last dec...

Early consistent measurement of intent to use automated vehicles will help explore the public’s reactions, improve the knowledge base, and facilitate an understanding of the potential benefits that could be achieved. Adopting a car technology acceptance model (CTAM), online surveys were implemented in several Texas cities including 2016 survey of D...

Background Active travel to and from a transit station may provide significant amounts of physical activity and improve health. The ease with which people can traverse the distance to the transit station may impede or support active travel. Therefore, transit stations that have features that are supportive of utilitarian physical activity would be...

As bicycling on roadways can cause adverse health effects, there is an urgent need to understand how bicycle routes expose bicyclists to traffic emissions. Limited resources for monitoring reveal that bicycle travel patterns may constrain such understanding at the network level. This study examined the potential exposure of bicyclists to traffic-re...

Recent studies have suggested that automobile pollution poses significantly more harmful health impacts than previously realized. Light-rail transit (LRT) is a major type of transportation infrastructure, but there has been little research assessing the air quality effects of LRT based on the actual air pollution data. This study aimed to assess th...

This guide describes scalable risk assessment methods for pedestrians and bicyclists, wherein risk is a measure of the probability of a crash to occur given exposure to potential crash events. This guide outlines eight sequential steps to develop risk values at various desired geographic scales, and describes the scope and nature of each step, incl...

Concerns regarding children's health and physical activity levels have prompted a growing interest in understanding the school mode choice decision. Walking and biking to school can help school-age children achieve recommended daily physical activity levels. The growing literature in this area has provided valuable insights but has often failed to...

Background Active travel can provide solutions to both public health and transportation sustainability issues. Switching from vehicle trips to active modes can bring traffic and safety gains, easing congestion and creating a safer, more walkable environment. Furthermore, active travel can contribute to reaching medically recommended levels of physi...

This study gathered empirical evidence on adoption patterns of self-driving vehicles, people's likely use of them, and how that might influence amount of travel, mode choice, auto ownership, and other travel behaviour decisions. Because self-driving vehicles are not yet on the market, a car technology acceptance model was applied to understand adop...

Transportation-related physical activity can significantly increase daily total physical activity through active transportation or walking/biking to transit stops. The purpose of this study was to assess the relations between transit-use and self-reported and monitor-based physical activity levels in a predominantly minority population from the Hou...

The growth of online shopping will likely impact rates of in-store shopping, signaling potentially significant ramifications for shopping-related vehicle travel. To better understand this relationship, we studied shoppers in Davis, California using a comprehensive survey dataset to explore the effect of personal characteristics, attitudes, percepti...

Background Policy makers are placing an increased emphasis on reducing automobile dependency and developing transportation systems that are multimodal. To help develop strategies to increase the use of alternative modes of transportation, the Texas A&M Transportation Institute (TTI) worked with the El Paso Metropolitan Planning Organization (MPO) o...

Background: Active travel has been linked with improved transportation and health outcomes, such as reduced traffic congestion and air pollution, improved mobility, accessibility and equity, and increased physical and mental health. The purpose of this study was to better understand active travel characteristics, motivators, and deterrents in the...

Objectives: This paper evaluates the changes in vehicle exhaust and stroke mortality for the general public residing in the surrounding area of the light rail transit (LRT) in Houston, Texas, after its opening. Methods: The number of daily deaths due to stroke for 2002-2005 from the surrounding area of the original LRT line (exposure group) and...

Light rail transit (LRT) has become a popular strategy to improve accessibility and mobility in the United States. It has also been touted as a tool to spur urban growth, higher-density development, and revitalization in large, auto-dependent cities like Houston, Texas. Although traditionally known as sprawling and highly auto-oriented, Houston has...

This report summarizes the variety of methods used to estimate and evaluate exposure to risk in pedestrian and bicyclist safety analyses. In the literature, the most common definition of risk was a measure of the probability of a crash to occur given exposure to potential crash events. There was also consensus on a theoretical definition of exposur...

This paper summarizes a component of a multimodal transportation study conducted for the El Paso Metropolitan Planning Organization of Texas, which included a regional population survey. The El Paso Regional Multimodal Transportation Survey was implemented between September and October 2015, and the study area included all of El Paso County, Texas,...

Recent studies on transit service through an equity lens have captured broad trends from the literature and national-level data or analyzed disaggregate data at the local level. This study integrates these methods by employing a geostatistical analysis of new transit access and income data compilations from the Environmental Protection Agency. By u...

Active transportation modes are increasingly being acknowledged for their individual and societal benefits. As a result, funding for pedestrian and bicycle infrastructure in the United States has increased substantially in recent years. However, pedestrian and bicycle equity impacts often go overlooked, which has resulted in an inequitable distribu...

Background Use of mass transit has been proposed as a way to incorporate regular physical activity into daily life because transit use typically requires additional travel to access and depart the stop or station. If this additional travel is active, a small but potentially important amount of physical activity can be achieved daily. Although prior...

Bike sharing can play a role in providing access to transit stations and then to final destinations, but early implementation of these systems in North America has been opportunistic rather than strategic. This study evaluates local intermodal plan goals using trip data and associated infrastructure such as transit stops and bike share station loca...

Policy makers and researchers are increasingly recognizing the connections between public health and transportation, but health improvements are typically framed from a physical health perspective rather than considering broader quality of life (QOL) impacts. Currently, there is a limited understanding of the ways in which transportation and QOL in...

This study gathered empirical evidence on adoption patterns of self-driving vehicles, people's likely use of them, and how that might influence amount of travel, mode choice, auto ownership, and other travel behaviour decisions. Because self-driving vehicles are not yet on the market, a car technology acceptance model was applied to understand adop...

This study gathered empirical evidence on adoption patterns of self-driving vehicles, people's likely use of them, and how that might influence amount of travel, mode choice, auto ownership, and other travel behaviour decisions. Because self-driving vehicles are not yet on the market, a car technology acceptance model was applied to understand adop...

Transit has the potential to increase an individual׳s level of physical activity due to the need to walk or bike at the beginning and end of each trip. Consideration of these health benefits would allow transit proponents to better demonstrate its true costs and benefits. In light of transit׳s potential health-related impacts, this study contribute...

Traditional methods of travel data collection are often limited by high costs, infrequent updates, or small sample sizes. Several emerging technologies, such as mobile phone positioning, global positioning system tracking, and Bluetooth re-identification, now allow for easier acquisition of long-term continuous trip data with little to no interacti...

This study gathered empirical evidence on adoption patterns of self driving vehicles, their likely use, and how that use might influence the amount of travel, mode choice, auto ownership, and other travel behavior decisions. Because self-driving vehicles were not yet on the market, a car technology acceptance model was applied to understand adoptio...

Growth in online shopping market share will likely lead to changes in consumer travel patterns. In response to the inevitable transportation impacts of online shopping, a detailed exploratory analysis of shopping survey data (excluding food purchases) was conducted with Davis, California, as a case study. Davis was notable for its lack of major big...

The U.S.–Mexico land border crossings are some of the busiest in the world. However, over the last several years, cross-border traffic has decreased significantly between El Paso, Texas, and Ciudad Juárez, Chihuahua, negatively impacting businesses in El Paso. The objective of this paper is to provide a synthesis of cross-border travel decision ana...

Background Policymakers and researchers are increasingly recognizing the connection between public health and transportation, but health improvements are typically framed from a physical activity or active travel perspective rather than considering broader quality of life impacts. Currently, there is an inadequate understanding of the ways in which...

Using Texas add-on sample data from the 2009 National Household Travel Survey, this study examines adult workers’ daily active choice decisions in the context of physical activity and attendant health benefits. The study looked at workers’ two choice behaviors: active activity and active travel. The first choice behavior, active activity, is develo...

With a population of about 145,000 people, Chittenden County, Vermont, has a metropolitan planning organization (MPO) that oversees approximately $30 million annually in transportation investments. Despite the county's small size, nonmotorized travel is an important element of the MPO's transportation planning efforts, as it is for many small and m...

This study jointly examines two distinct ICT choice behaviors—telecommuting and teleshopping—along two different dimensions: adoption and frequency. The linkages between two adoption models, or the two frequency models, are obtained by adopting a flexible copula-based approach that accommodates dependency (results from unobserved factors) between i...

The current article proposes an approach to accommodate flexible spatial dependency structures in discrete choice models in general, and in unordered multinomial choice models in particular. The approach is applied to examine teenagers’ participation in social and recreational activity episodes, a subject of considerable interest in the transportat...

The objective of this study is to contribute to the telecommuting literature by jointly examining the propensity and frequency of workers to telecommute, using a rich set of individual demographics, work-related and industry characteristics, household demographics, and commute-trip/work-location characteristics. The data are drawn from the Chicago...

The current paper focuses on analyzing and modeling the physical activity participation levels (in terms of the number of daily "bouts" or "episodes" of physical activity during a weekend day) of all members of a family jointly. Essentially, we consider a family as a "cluster" of individuals whose physical activity propensities may be affected by c...

A study was done to shed light on the determinants of working from home beyond the traditional office-based work hours. The frequency of work participation from home was examined for individuals who also have a traditional work pattern of traveling to an out-of-home work-place and a fixed number of work hours at the out-of-home workplace. The sampl...

This study proposes a simple and practical Composite Marginal Likelihood (CML) inference approach to estimate ordered-response discrete choice models with flexible copula-based spatial dependence structures across observational units. The approach is applicable to data sets of any size, provides standard error estimates for all parameters, and does...

Residential relocation or mobility is a critical component of land use dynamics. Models of land use dynamics need to consider residential relocation or mobility behavior of households to be able to predict population demographics land use patterns that are critical to activity and travel demand forecasting. Unfortunately, little is known about resi...

The factors influencing the decision to bicycle are explored and unraveled to inform the development of appropriate and effective strategies to increase bicycling and promote the health of individuals and of the environment. The data used in the analysis were drawn from a survey of Texas bicyclists, and the study includes a comprehensive explanator...

This study focuses on accommodating spatial dependency in data indexed by geographic location. In particular, the emphasis is on accommodating spatial error correlation across observational units in binary discrete choice models. We propose a copula-based approach to spatial dependence modeling based on a spatial logit structure rather than a spati...

This paper offers a comprehensive analysis of physical recreational activity engagement by simultaneously examining the location, time of day, day of week, and social context of these activities. Data from the 2007 American Time Use Survey is used to estimate a mixed multiple discrete continuous extreme value (MDCEV) model that simultaneously captu...

In the US, the rise in motorized vehicle travel has contributed to serious societal, environmental, economic, and public health problems. These problems have increased the interest in encouraging non-motorized modes of travel (walking and bicycling). The current study contributes toward this objective by identifying and evaluating the importance of...

This study presents a unified framework to understand the weekday recreational activity participation time-use of adults, with an emphasis on the time expended in physically active recreation pursuits by location and by time-of-day. Such an analysis is important for a better understanding of how individuals incorporate physical activity into their...

ABSTRACT

This paper describes the development of a population update modeling system as part of the development of the comprehensive econometric microsimulator for socioeconomics, land use, and transportation systems (CEMSELTs). which is part of the comprehensive econometric microsimulator for urban systems (CEMUS) under development at the University of Tex...

This paper presents a modeling methodology capable of accounting for spatial correlation across choice alternatives in discrete choice modeling applications. Many location choice (e.g., residential location, workplace location, destination location) modeling contexts involve choice sets where alternatives are spatially correlated with one another d...

This paper presents a detailed analysis of discretionary leisure activity engagement by children. Children’s leisure activity engagement is of much interest to transportation professionals from an activity-based travel demand modeling perspective, to child development professionals from a sociological perspective, and to health professionals from a...

This paper examines the discretionary time-use of children, including the social context of children’s participations. Specifically, the paper examines participation and time investment in in-home leisure as well as five different types of out-of-home discretionary activities: (1) shopping, (2) social, (3) meals, (4) passive recreation (i.e., physi...

The Comprehensive Econometric Micro-simulator for Daily Activity-travel Patterns (CEMDAP) is a micro-simulation implementation of a continuous-time activity-travel modeling system. Given as input various socio-demographic, land-use, and transportation level-of-service attributes, the system provides as output the complete daily activity-travel patt...