Modeling

Estimating Hybrid Choice Models with Biogeme

Bierlaire, Michel
Ben-Akiva, Moshe
Joan Walker
2026

The literature on discrete choice models with latent variables is vast (Walker, 2001, Ashok et al., 2002, Greene and Hensher, 2003, Ben-Akiva, Walker, Bernardino, Gopinath, Morikawa and Polydoropoulou, 2002, Ben-Akiva et al., 2002, to cite just a few early references). This document presents a practical introduction to the specification and estimation of hybrid choice models using Biogeme. It introduces the main concepts and notation underlying these models, discusses the associated normalization issues, and illustrates their implementation through a sequence of progressively richer...

Staging at the Curb: Evaluating the Impacts of Shared Automated Vehicle Fleet Operations Under Curb Usage Restrictions

Bahk, Younghun
Hyland, Michael
Susan Shaheen
Wolfe, Brooke
Adam Cohen
2026

Shared automated vehicle (SAV) ridehailing services are now operating in several metropolitan regions in the United States. While providing benefits, SAV services may exacerbate issues related to curb usage and vehicle kilometers traveled (VKT) in urban areas. The objective of this study is to provide guidance to cities by evaluating the impacts of SAVs’ short-term curb usage for staging between serving ride requests, under different curb restrictions and SAV operational strategies. We focus on the following performance metrics: VKT, curb productivity, customer wait time, and customer...

Extended Discrete Choice Models: Integrated Framework, Flexible Error Structures, and Latent Variables

Joan Walker
2001

Discrete choice methods model a decision-maker’s choice among a set of mutually exclusive and collectively exhaustive alternatives. They are used in a variety of disciplines (transportation, economics, psychology, public policy, etc.) in order to inform policy and marketing decisions and to better understand and test hypotheses of behavior. This dissertation is concerned with the enhancement of discrete choice methods.

Integrated Approach to Sustainable Transportation, Land Use, and Building Design: Case of Luokou District, Jinan, China

Manish Shirgaokar
Elizabeth Deakin
Xinlan Zhang
2010

Due the pace and the scale of urban development in China, the implementation of sustainable urban practices there is an essential step in addressing climate change. Chinese officials are becoming increasingly interested in sustainable practices including transit-oriented development (TOD). However, even though the concept of TOD is supported, implementation sometimes falls short of desirable outcomes. In this paper, we present the preliminary results from a collaborative project carried out with planning officials from the city of Jinan (pop. 3.4 million), for a 3.1 km2 (1.15 mi2) district...

Determinants of Sustainable Mode Choice in Different Socio-Cultural Contexts: A comparison of Rome and San Francisco

Samira Ramezani
Barbara Pizzo
Elizabeth Deakin
2018

This paper is a part two of a study investigating the relative importance of the built environment, socio-demographic, and attitudinal factors on mode choice. A semi-experimental approach that aims to measure causal effects of the built environment is utilized. This paper reports spatial analysis, survey and modeling results for San Francisco, CA, USA and compares the results with a previous similar study in Rome, Italy. Results reveal that the local street network's integration is important in both cities and that in both cases built environment seems to have higher impact on mode choice...

Built Environment versus Personal Traits: an Application of Integrated Choice and Latent Variable Model (ICLV) in Understanding Modal Choice in Rome, Italy

Samira Ramezani
Barbara Pizzo
Elizabeth Deakin
2015

In spite of numerous applications of Integrated Choice and Latent Variable (ICLV) modelling in the field of transportation engineering, there is no published work applying it in studies of the effect of built environment on modal choice. This study uses an ICLV model to investigate the relative importance of built environment versus personal traits. It designs a quasiexperiment to elicit a better understanding of the causal effects of several urban form characteristics on modal choice. Findings suggest that built form can compete with the magnitude of the influence of personal traits, if...

Transferable Human Mobility Network Reconstruction with neuroGravity

Yang, Jinming
Huang, Shaoyu
Huang, Zongyuan
Jin, Yaohui
Cao, Xiaokang
Marta Gonzalez
2026

Accurate modeling of human mobility is critical for tackling urban planning and public health challenges. In undeveloped regions, the absence of comprehensive travel surveys necessitates reconstructing mobility networks from publicly available data. Here we develop neuroGravity, a physics-informed deep learning model that reliably reconstructs mobility flows from limited observations and transfers to unobserved cities. Using only urban facility and population distributions, we find that neuroGravity's regional representations strongly correlate with socioeconomic and livability status,...

A Total Cost of Ownership Model for Low Temperature PEM Fuel Cells in Combined Heat and Power and Backup Power Applications

Max Wei
Tim Lipman
Ahmad Mayyas
Joshua Chien
Shuk Han Chan
David Gosselin
Hanna Breunig
Michael Stadler
Thomas McKone
Paul Beattie
Patricia Chong
Whitney Colella
Brian James
2014

A total cost of ownership model is described for low temperature proton exchange membrane stationary fuel cell systems for combined heat and power (CHP) applications from 1-250kW and backup power applications from 1-50kW. System designs and functional specifications for these two applications were developed across the range of system power levels. Bottom-up cost estimates were made for balance of plant costs, and detailed direct cost estimates for key fuel cell stack components were derived using design-for-manufacturing-and-assembly techniques. The development of high throughput,...

SMART Mobility. Advanced Fueling Infrastructure Capstone Report

John Smart
Zicheng Bi
Alicia Birky
Brennan Borlaug
Erin Burrell
Eleftheria Koutou
Dong-Yeon Lee
Tim Lipman
Andrew Meintz
Eric Miller
Ahmed Mohamed
Matthew Moniot
Amy Moore
Yutaka Motoaki
Zachary Needell
Omer Onar
Clement Rames
Nicholas Reincke
Mohammad Roni
Shawn Salisbury
Colin Sheppard
Danho Ange Lionel Toba
Victor Walker
Dustin Weigl
Eric Wood
Fei Xie
Yonggen Yi
Teng Zeng
Hongcai Zhang
Yan Zhou
Zhi Zhou
2020

The U.S. Department of Energy’s Systems and Modeling for Accelerated Research in Transportation (SMART) Mobility Consortium is a multiyear, multi-laboratory collaborative, managed by the Energy Efficient Mobility Systems Program of the Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, dedicated to further understanding the energy implications and opportunities of advanced mobility technologies and services. The first three-year research phase of SMART Mobility occurred from 2017 through 2019 and included five research pillars: Connected and Automated Vehicles,...

Reducing Greenhouse Emissions and Fuel Consumption: Sustainable Approaches for Surface Transportation

Susan Shaheen
Tim Lipman
2007

Climate change is rapidly becoming known as a tangible issue that must be addressed to avoid major environmental consequences in the future. Recent change in public opinion has been caused by the physical signs of climate change–melting glaciers, rising sea levels, more severe storm and drought events, and hotter average global temperatures annually. Transportation is a major contributor of carbon dioxide (CO2) and other greenhouse gas emissions from human activity, accounting for approximately 14 percent of total anthropogenic emissions globally and about 27 percent in the U.S....