Data

The Influence of Social Contacts and Communication Use on Travel Behavior: A Smartphone-Based Study

Ythier, Jeanne
Walker, Joan L.
Bierlaire, Michel
2013

This paper explores the potential of a smartphone database to investigate influences on travel behavior. The aim is to exploit the rich individual-level data available from the smartphone to study the influence of communication and social contacts (collected via phone call and short message service (SMS) logs) on spatial movement (collected via Global Positioning System (GPS)). An advantage of smartphone data is the ability to collect such rich data without user input over a long period of time, and the disadvantages is the difficulty associated with processing the data. The authors...

The San Francisco Travel Quality Study: Tracking Trials and Tribulations of a Transit Taker

Carrel, Andre
Sengupta, Raja
Walker, Joan L.
2017

In helping understand the dynamics of travel choice behavior and traveler satisfaction over time, multi-day panel data is invaluable (McFadden in Am Econ Rev 91(3): 351–378, 2001). The collection of such data has become increasingly feasible thanks to smartphones, which researchers can use to present surveys to travelers and to collect additional information through the phones’ location services and other sensors. This paper describes the design and implementation of the San Francisco Travel Quality Study, a multi-day research study conducted in autumn 2013 with 838 participants. The...

Tracking the State and Behavior of People in Response to COVID-1 19 Through the Fusion of Multiple Longitudinal Data Streams

Bouzaghrane, Mohamed
Obeid, Hassan
Hayes, Drake
Chen, Minnie
Li, Meiqing
Parker, Madeleine
Rodríguez, Daniel A.
Chatman, Daniel G.
Frick, Karen Trapenberg
Sengupta, Raja
Walker, Joan
2022

The changing nature of the COVID-19 pandemic has highlighted the importance of comprehensively considering its impacts and considering changes over time. Most COVID-19 related research addresses narrowly focused research questions and is therefore limited in addressing the complexities created by the interrelated impacts of the pandemic. Such research generally makes use of only one of either 1) actively collected data such as surveys, or 2) passively collected data. While a few studies make use of both actively and passively collected data, only one other study collects it longitudinally...

Transportation Impacts of Information Provision & Data Collection via Smartphones

Vautin, David A.
Walker, Joan L.
2011

The proliferation of smartphones over the next decade, with their abilities to provide personalized travel information and collect highly detailed data, will likely have significant impacts on transportation operations, systems planning, and travel behavior. Three core issues are studied to understand these impacts. First, the authors examine the key differences between past intelligent transportation systems (ITS) efforts and new opportunities made possible by the rapid proliferation of smartphones. Second, system frameworks for data collection and information provision are...

Travel Demand Models in the Developing World: Correcting for Measurement Errors

Walker, Joan
Li, Jieping
Srinivasan, Sumeeta
Bolduc, Denis
2010

While transport modelers in developed countries are accustomed to working with relatively rich datasets including transport networks and land use data, such databases are rarely available in developing countries. However, developing countries such as China with its immense rate of economic growth are, arguably, most in need of demand models. The research addressed in this paper is how to develop mode choice models for planning and policy analysis when level of service data are not available and resources are limited. The research makes use of a 1,001 household travel and activity survey...

Understanding Future Mode Choice Intentions of Transit Riders as a Function of Past Experiences with Travel Quality

Carrel, Andre
Walker, Joan L.
2017

This paper empirically investigates the causes for transit use cessation, focusing on the influence of users’ personal experiences, resulting levels of satisfaction, and subsequent behavioral intentions. It builds on a novel data set in which observed, objective measures of travel times are mapped to smartphone-based surveys where participants assess their travel experience. An integrated choice and latent variable model is developed to explain the influence of satisfaction with operations (travel times) and satisfaction with the travel environment (e.g., crowding) on behavioral intentions...

Freeway Performance Measurement System (PeMS), PeMS 6: Final Report for CCIT TO 15

Varaiya, Pravin
2006

PeMS 6 is the latest of six task orders devoted to research, development, and maintenance of the PeMS system. PeMS collects, processes, stores, and makes available online data from eight Caltrans districts (D3, 4, 5, 6, 7, 8, 11, 12). The data are obtained from 22,067 loops1, grouped into 8,649 vehicle detector stations (VDS). These loops cover 3,154 out of 30,572 directional-miles of interstate and state highways in California. PeMS began as a research project. As the research system evolved, Caltrans determined that the information it provided was very valuable, and additional resources...

A Data-Centric Weak Supervised Learning for Highway Traffic Incident Detection

Sun, Yixuan
Mallick, Tanwi
Balaprakash, Prasanna
Macfarlane, Jane
2022

Using the data from loop detector sensors for near-real-time detection of traffic incidents on highways is crucial to averting major traffic congestion. While recent supervised machine learning methods offer solutions to incident detection by leveraging human-labeled incident data, the false alarm rate is often too high to be used in practice. Specifically, the inconsistency in the human labeling of the incidents significantly affects the performance of supervised learning models. To that end, we focus on a data-centric approach to improve the accuracy and reduce the false alarm rate of...

A Machine Learning Method for Predicting Traffic Signal Timing from Probe Vehicle Data

Ugirumurera, Juliette
Severino, Joseph
Bensen, Erik A.
Wang, Qichao
Macfarlane, Jane
2023

Traffic signals play an important role in transportation by enabling traffic flow management, and ensuring safety at intersections. In addition, knowing the traffic signal phase and timing data can allow optimal vehicle routing for time and energy efficiency, eco-driving, and the accurate simulation of signalized road networks. In this paper, we present a machine learning (ML) method for estimating traffic signal timing information from vehicle probe data. To the authors best knowledge, very few works have presented ML techniques for determining traffic signal timing parameters from...

Data-Driven Energy Use Estimation in Large Scale Transportation Networks

Wang, Bin
Chan, Cy
Somasi, Divya
Macfarlane, Jane
Rask, Eric
2019

Energy consumption in the transportation sector accounts for 28.8% of the total value among all the industry sectors in the United States, reaching 28.2 quadrillion btu in 2017. Having an accurate evaluation of the vehicle fuel and energy consumption values is a challenging task due to numerous implicit influential factors, such as the variety of powertrain configurations, time-varying traffic and congestion patterns, and emerging new technologies, such as regenerative braking. In this paper, we propose to present a data-driven computational framework to evaluate the energy impact on the...