published journal article

Predicting the market penetration of electric and clean-fuel vehicles

Science of The Total Environment

Publication Date

June 1, 1993

Author(s)

Thomas Golob, Ryuichi Kitamura, Mark Bradley, David Bunch

Abstract

Air quality in Southern California and elsewhere could be substantially improved if some gasoline-powered personal vehicles were replaced by vehicles powered by electricity or alternative fuels, such as methanol, ethanol, propane, or compressed natural gas. Quantitative market research information about how consumers are likely to respond to alternative-fuel vehicles is critical to the development of policies aimed at encouraging such technological change. In 1991, a three-phase stated preference (SP) survey was implemented in the South Coast Air Basin of California to predict the effect on personal vehicle purchases of attributes that potentially differentiate clean-fuel vehicles from conventional gasoline (or diesel) vehicles. These attributes included: limited availability of refueling stations, limited range between refueling or recharging, vehicle prices, fuel operating costs, emissions levels, multiple-fuel capability and performance. Respondents were asked to choose one vehicle from each of five sets of hypothetical clean-fuel and conventional gasoline vehicles, each vehicle defined in terms of attributes manipulated according to a specific experimental design. Discrete choice models, such as the multinominal logit model, are then used to estimate how the values of the attribute levels influence purchase decisions. The SP survey choice sets were customized to each respondent’s situation, as determined in the preceding phase of the survey. The final phase of the survey involved fuel-choice SP tasks for multi-fuel vehicles that can run on either clean fuels or gasoline. Preliminary results from a pilot sample indicate that the survey responses are plausible and will indeed be useful for forecasting.

Suggested Citation
Thomas F Golob, Ryuichi Kitamura, Mark Bradley and David S Bunch (1993) “Predicting the market penetration of electric and clean-fuel vehicles”, Science of The Total Environment, 134(1-3), pp. 371–381. Available at: 10.1016/0048-9697(93)90367-f.

published journal article

Automated time activity classification based on global positioning system (GPS) tracking data

Environmental health : a global access science source

Publication Date

November 1, 2011

Author(s)

Jun Wu, Chengsheng Jiang, Doug Houston, Dean Baker, Ralph Delfino
Suggested Citation
Jun Wu, Chengsheng Jiang, Douglas Houston, Dean Baker and Ralph Delfino (2011) “Automated time activity classification based on global positioning system (GPS) tracking data”, Environmental health : a global access science source, 10(1). Available at: 10.1186/1476-069x-10-101.

research report

Policy and Literature Review on the Effect Millennials Have on Vehicle Miles Traveled, Greenhouse Gas Emissions, and the Built Environment

Abstract

Vehicle travel has reduced substantially across all demographics in the 2000’s, but millennials or young adults born from 1985-2000 stand out as the group that has reduced vehicle travel the most. This reduction of travel among millennials is known as the millennial effect. This policy and literature review discusses insights from recent policy reports and literature regarding the millennial effect and identifies the prominent themes and gaps in our knowledge. The first section reviews existing research on the millennial effect on vehicle miles traveled (VMT). The second section discusses the influence of the built environment on the travel and activities of the millennial generation. The third section highlights scenarios describing the millennials effect’s potential magnitude and identifies topics for consideration in future scenario planning efforts. The final section discusses the uncertainty that exists regarding the future behavior of millennials and their influence on VMT and greenhouse gas emissions.

Suggested Citation
Stephen G. Ritchie, Doug Houston and Michelle E. Zuñiga (2017) Policy and Literature Review on the Effect Millennials Have on Vehicle Miles Traveled, Greenhouse Gas Emissions, and the Built Environment. Available at: https://escholarship.org/uc/item/8dc5g9d8 (Accessed: October 11, 2023).

published journal article

A generalized diffusion model for preference and response time: Application to ordering mobility-on-demand services

Transportation Research Part C: Emerging Technologies

Publication Date

December 1, 2020

Abstract

The goal of this research study is to model user preferences and response times (RTs) jointly in the context of Mobility-on-Demand (MOD) services under different MOD operator pricing schemes, information frames, and pressure levels. MOD operators’ information provision, delay, and vehicle allocation strategies influence users’ preferences and RTs, which, in turn, affect which operational and information provision strategies are optimal for MOD operators. Evidence shows that preferences and RTs are sensitive to precedent decisions, information frames, risk, and time pressure. These dynamic interplaying factors are challenging to capture using a traditional discrete choice modeling framework. Hence, this study proposes a generalized diffusion model based on Decision Field Theory (DFT), multi-attribute Prospect Theory (PT), and Random Utility Theory to model these various interplaying factors. This study applies the proposed modeling approach in the context of ordering Shared-use Automated Vehicle Mobility Services (SAMS). Sensitivity analyses explore the impacts of various inputs and model parameters such as initial waiting time estimate, updated waiting time estimate, time pressure, loss aversion, and value-of-time on preferences and RTs. The proposed model can provide value to MOD operators in terms of information provision and pricing strategies. Moreover, the proposed model can assist policymakers and planners interested in the system impacts of MOD services and regulating MOD information provision and pricing strategies. The modeling framework can extend to other applications where multiple sub-decisions are necessary to make a single (travel) choice under information update, framing, risk, and time pressure.

Suggested Citation
Jiangbo Yu and Michael F. Hyland (2020) “A generalized diffusion model for preference and response time: Application to ordering mobility-on-demand services”, Transportation Research Part C: Emerging Technologies, 121, p. 102854. Available at: 10.1016/j.trc.2020.102854.

research report

Resilience and Validation of GNSS PNT Solutions

Publication Date

November 20, 2023

Author(s)

Todd E. Humphreys, Qi Alfred Chen, Umit Ozguner, Charles Toth

Abstract

Highly automated transportation systems rely on a steady stream of signals and information from external sources for localization, route planning, perception, and general situational awareness. This includes reliance on positioning, navigation, and timing (PNT) information: Location is essential autonomous navigation and planning; and accurate timing is a precondition for on-board sensor fusion, cooperative control, and management based on information from other vehicles or the infrastructure. It is crucial to identify schemes for GNSS signal authentication and resilience that are well-suited for highly autonomous vehicles (HAVs). HAVs require PVT sensing techniques that are resilient to unusual natural or accidental events and secure against deliberate attack.

Suggested Citation
Todd E. Humphreys, Qi Alfred Chen, Umit Ozguner and Charles Toth (2023) Resilience and Validation of GNSS PNT Solutions. Final Report. Available at: https://rosap.ntl.bts.gov/view/dot/72661.

conference paper

On the existence of stationary states in general road networks

21st international symposium on transportation and traffic theory

Publication Date

January 1, 2015

Author(s)

Abstract

Our daily driving experience and empirical observations suggest that traffic patterns in a road network are relatively stationary during peak periods. In numerous transportation network studies, there has been an implicit conjecture that stationary states exist in a network when origin demands, route choice proportions, and destination supplies are constant. In this study, we first rigorously formulate the conjecture within the framework of a network kinematic wave theory with an invariant junction model. After defining stationary states, we derive a system of algebraic equations in 3-tuples of stationary link flow-rates, demands, and supplies. We then introduce a new definition of junction critical demand levels based on effective demands and supplies. With a map in critical demand levels, we show that its fixed points and, therefore, stationary states exist with the help of Brouwer’s fixed point theorem. For two simple road networks, we show that the map is well-defined and can be used to solve stationary states with a brute-force method. Finally we summarize the study and present some future extensions and applications. (C) 2015 The Authors. Published by Elsevier B.V.

Suggested Citation
Wen-Long Jin (2015) “On the existence of stationary states in general road networks”, in . Kuwahara, M and Kita, H and Asakura, Y (ed.) 21st international symposium on transportation and traffic theory. ELSEVIER SCIENCE BV (Transportation research procedia), pp. 689–703. Available at: 10.1016/j.trpro.2015.06.036.

conference paper

Freeway incident detection using artificial neural networks

Proceedings, International Conference on Artificial Intelligence Applications in Transportation Engineering

Publication Date

January 1, 1998
Suggested Citation
S. G. Ritchie, Ruey L. Cheu and W. W. Recker (19982) “Freeway incident detection using artificial neural networks”, in Proceedings, International Conference on Artificial Intelligence Applications in Transportation Engineering. San Bueneventura, California.

published journal article

Microscopic-macroscopic models systems integration: A simulation case study for ATMIS

SIMULATION

Publication Date

May 1, 2005

Author(s)

Abd-El-Kader Sahraoui, R. (Jay) Jayakrishnan
Suggested Citation
Abd-El-Kader Sahraoui and R. Jayakrishnan (2005) “Microscopic-macroscopic models systems integration: A simulation case study for ATMIS”, SIMULATION, 81(5), pp. 353–363. Available at: 10.1177/0037549705052771.

published journal article

Another view of freight forecasting modeling trends

Ksce Journal of Civil Engineering

Publication Date

March 1, 2010

Author(s)

Choong Heon Yang, Amelia Regan, Young Tae Son
Suggested Citation
ChoongHeon Yang, Amelia C. Regan and Young Tae Son (2010) “Another view of freight forecasting modeling trends”, Ksce Journal of Civil Engineering, 14(2), pp. 237–242. Available at: 10.1007/s12205-010-0237-y.

conference paper

Automated Discovery of {Denial-of-Service} Vulnerabilities in Connected Vehicle Protocols

30th USENIX Security Symposium (USENIX Security 21)

Publication Date

January 1, 2021

Author(s)

Shengtuo Hu, Qi Alfred Chen, Zhe (Jared) Sun, Yiheng Feng, Z. Morley Mao, Henry Liu
Suggested Citation
Shengtuo Hu, Qi Alfred Chen, Jiachen Sun, Yiheng Feng, Z. Morley Mao and Henry X. Liu (2021) “Automated Discovery of {Denial-of-Service} Vulnerabilities in Connected Vehicle Protocols”, in 30th USENIX Security Symposium (USENIX Security 21), pp. 3219–3236. Available at: https://www.usenix.org/conference/usenixsecurity21/presentation/hu-shengtuo (Accessed: October 11, 2023).