working paper

A Joint Household Travel Distance Generation And Car Ownership Model

Publication Date

March 1, 1989

Associated Project

Working Paper

Reprint No. 8

Areas of Expertise

Abstract

The product of this research is a dynamic simultaneous equations model of car ownership and modal travel distances as a function of income. The data are from the Dutch National Mobility Panel (1984-1987); and four modes are encompassed: car driver, car passenger, train, and bus-tram-subway. A novel feature of the simultaneous equation system is the consistent treatment of the measurement scales of the variables: ordered probit functions for income and car ownership and tobit functions for distances. The dynamics are expressed in terms of pooled panel survey measurements of the variables at two points in time one year apart. This allows the identification of lagged responses and serial correlations over a one-year time-horizon. Results indicate that increased car ownership and car kilometers at time T2 is influenced by heavy usage of other modes at time T1. This indicates there are significant noninstantaneous adjustments of car ownership and usage that represent modal substitutions.

Suggested Citation
Thomas F. Golob and Leo Van Wissen (1989) A Joint Household Travel Distance Generation And Car Ownership Model. Working Paper Reprint No. 8. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/72h4k912.

published journal article

The Association Between Ambient Fine Particulate Matter and Spontaneous Preterm Birth: Evidence From a Large Pregnancy Cohort in Southern California [ID 1244]

Obstetrics & Gynecology

Publication Date

June 1, 2025

Author(s)

Alexa N. Reilly, Anqi Jiao, Tarik Benmarhnia, Yi Sun, Chantal Avila, Jun Wu

Abstract

INTRODUCTION:  Although studies have found positive associations between exposure to PM2.5 and preterm birth, distinguishing between spontaneous preterm birth (sPTB) and iatrogenic preterm birth (iPTB) was a challenge in previous research. This study examined associations between total PM2.5 and PM2.5 constituent exposure and sPTB. METHODS:  This is a retrospective cohort study from 2008 to 2018 of singleton live births within a large health care system in southern California, United States. Daily total PM2.5 concentrations and monthly data on five PM2.5 constituents (sulfate, nitrate, ammonium, organic matter, and black carbon) were obtained. The average concentrations of total PM2.5 and constituents were calculated over the pregnancy and by trimester. A novel natural language processing algorithm was used to identify sPTB in medical records. Discrete-time survival models were used to estimate the associations of total PM2.5 and constituents with sPTB. Effect modifiers included maternal race/ethnicity, educational attainment, household income, and green space. RESULTS:  There were 19,341 (4.7%) sPTBs among 409,037 births. We observed significant associations of sPTB with PM2.5, black carbon, nitrate, and sulfate. The second trimester was the most susceptible window. Significantly higher associations with PM2.5 were observed among mothers with lower educational attainment, lower income, and less green space exposure. CONCLUSIONS/IMPLICATIONS:  Maternal exposures to PM2.5 and specific PM2.5 constituents were associated with an increased risk of sPTB. Mothers with lower socioeconomic status were vulnerable, whereas green space was a protective effect modifier.

Suggested Citation
Alexa N. Reilly, Anqi Jiao, Tarik Benmarhnia, Yi Sun, Chantal Avila and Jun Wu (2025) “The Association Between Ambient Fine Particulate Matter and Spontaneous Preterm Birth: Evidence From a Large Pregnancy Cohort in Southern California [ID 1244]”, Obstetrics & Gynecology, 145(6S), p. 40S. Available at: 10.1097/AOG.0000000000005917.037.

Phd Dissertation

Commercial vehicle classification system using advanced inductive loop technology

Abstract

Commercial vehicles typically represent a small fraction of vehicular traffic on most roadways. However, their influence on the economy, environment, traffic performance, infrastructure, and safety are much more significant than their diminutive numerical presence suggests. This dissertation describes the development and prototype implementation of a new high-fidelity inductive loop sensor and a ground-breaking commercial vehicle classification system based on the vehicle inductive signatures obtained from this sensor technology. This new sensor technology is relatively easy to install and has the potential to yield reliable and highly detailed vehicle inductive signatures for advanced traffic surveillance applications. The Speed PRofile INterpolation Temporal-Spatial (SPRINTS) transformation model developed in this dissertation improves vehicle signature data quality under adverse traffic conditions where acceleration and deceleration effects can distort inductive vehicle signatures. The axle classification model enables commercial vehicles to be classified accurately by their axle configuration. The body classification models reveal the function and unique impacts of the drive and trailer units of each commercial vehicle. Together, the results reveal the significant potential of this inductive sensor technology in providing a more comprehensive commercial vehicle data profile based on a unique ability to extract both axle configuration information as well as high fidelity undercarriage profiles within a single sensor technology to provide richer insight on commercial vehicle travel statistics.

Suggested Citation
Yeow Chern Andre Tok (2008) Commercial vehicle classification system using advanced inductive loop technology. Ph.D.. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/1go3t9q/alma991035092965004701 (Accessed: October 14, 2023).

Phd Dissertation

Combinatorial auctions: Applications in freight transportation contract procurement

Publication Date

June 30, 2003

Abstract

This dissertation focuses on the development of optimization methods and approximation algorithms for combinatorial auctions, particularly with application to the contract procurement problem in freight transportation. Combinatorial auctions are auctions in which a set of heterogeneous items are sold simultaneously and in which bidders can bid for their preferred combinations of items. They involve many difficult optimization problems both for auction hosts and bidders and have received significant attention from computer scientists, operations researchers and economists recently. Large shippers (typically manufacturing companies or retailers) have begun to use this method to procure services from trucking companies and logistics services providers. This dissertation first analyzes the economic impact of combinatorial auction-based procurement methods both on shippers and carriers using a simulation study and reveals that both parties can benefit from this economically efficient price discovery mechanism. While the majority of prior research has been from an auctioneer’s perspective, we demonstrate that bidders have even more complicated optimization problems in combinatoiral auctions. The bid construction problem, that is, how bidders should identify and construct beneficial bids, is very hard and remains an open question. This dissertation investigates this problem and proposes an optimization based approximation method that involves solving an NP-hard problem only once, yielding significant improvements in computational efficiency. Further, the current state of trucking and third party logistics industries are examined. The trucking industry is very competitive and small carriers are operating under thin margins. This dissertation addresses these issues by proposing an auction based collaborative carrier network in which participating carriers can identify inefficient lanes from daily operations quickly and exchange them with partners under an auction protocol. This system is proved to be Pareto efficient. Further, decision problems are discussed regarding how carriers should identify inefficient operations and how to make and select bids. This represents an effort to use advanced auction mechanisms to enhance the carriers’ operational efficiencies.

Suggested Citation
Jiongjiong Song (2003) Combinatorial auctions: Applications in freight transportation contract procurement. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991035093498004701.

published journal article

An extension of Newell's simplified kinematic wave model to account for first-in-first-out violation: With an application to vehicle trajectory estimation

Transportation Research Part C: Emerging Technologies

Publication Date

December 1, 2019
Suggested Citation
Adrian Rey, Wen-Long Jin and Stephen G. Ritchie (2019) “An extension of Newell's simplified kinematic wave model to account for first-in-first-out violation: With an application to vehicle trajectory estimation”, Transportation Research Part C: Emerging Technologies, 109, pp. 79–94. Available at: 10.1016/j.trc.2019.10.005.

published journal article

Asymptotic traffic dynamics arising in diverge–merge networks with two intermediate links

Transportation Research Part B: Methodological

Publication Date

June 1, 2009

Author(s)

Suggested Citation
Wen-Long Jin (2009) “Asymptotic traffic dynamics arising in diverge–merge networks with two intermediate links”, Transportation Research Part B: Methodological, 43(5), pp. 575–595. Available at: 10.1016/j.trb.2008.10.002.

published journal article

Association of urban green space with metabolic syndrome and the role of air pollution

Landscape and Urban Planning

Publication Date

August 1, 2024

Author(s)

Yi Sun, Yunli Chen, Yuanyuan Huang, Yan Luo, LiPing Yan, Sailimai Man, Canqing Yu, Jun Lv, Chuangshi Wang, Jun Wu, Heling Bao, Bo Wang, Liming Li, Hui Liu
Suggested Citation
Yi Sun, Yunli Chen, Yuanyuan Huang, Yan Luo, LiPing Yan, Sailimai Man, Canqing Yu, Jun Lv, Chuangshi Wang, Jun Wu, Heling Bao, Bo Wang, Liming Li and Hui Liu (2024) “Association of urban green space with metabolic syndrome and the role of air pollution”, Landscape and Urban Planning, 248, p. 105100. Available at: 10.1016/j.landurbplan.2024.105100.

Phd Dissertation

A dynamic household alternative-fuel vehicle demand model using stated and revealed transaction information.

Abstract

Forecasting the demand for alternative-fuel vehicles (AFVs) is quite important for manufacturers, fuel suppliers and environmental planners. AFVs have attributes such as reduced range and limited refueling options that are very different from existing vehicles. Therefore stated preference (SP) data is necessary for demand models. Previous work by Brownstone, Bunch, and Train (1998) shows that there are serious biases in these stated preference data. Another source of households’ vehicle preference, is households’ actual observed transaction behavior (Revealed preference (RP) data). I develop a dynamic stated and revealed preference vehicle transaction model which uses the RP data to control for the biases of using pure SP data in order to better forecast households’ demand for AFVs for California. I implement a “scale factor” to specify the relationship of the different variances of the RP and SP data. Moreover, I examine the nested structure over different fuel-type vehicle choices and estimate both the multinomial logit (MNL) and nested logit (NL) models. In addition, I conduct forecast using the pure SP and joint SP-RP MNL models under the scenario consisting of new vehicle technologies for year 1998. Compared to the new vehicle sales statistics, it is obvious that the joint SP-RP model provides more reasonable forecasts. I also examine the different substitution patterns implied by the pure SP MNL and NL models when new vehicle choices are introduced. The NL model predicts more realistic substitution pattern. I also add the used vehicle choices to the forecast scenario to make the forecast more realistic because the used vehicle market is taken into consideration. Large panel data sets have been collected by the California Alternative-Fuel Vehicle Demand Forecast Project since May 1993. These data contain extensive information on households’ stated and revealed preference vehicle transactions, vehicle utilization and households’ socioeconomic characteristics. This study serves as an example of how to forecast new products or technologies that mark considerable departures from existing products or technologies.

Suggested Citation
Hongyan Sheng (1999) A dynamic household alternative-fuel vehicle demand model using stated and revealed transaction information.. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991035093101304701.

research report

Using UMTA Section 15 data for triennial reviews

Publication Date

June 1, 1987

Author(s)

Gordon (Pete) Fielding, Mark. Yamarone, Marcy Jaffe

Final Report

CA-06-0213-3

Areas of Expertise

Abstract

Illustrates the application of the Irvine Performance Evaluation Method (IPEM) to triennial reviews of transit performance conducted by the Urban Mass Transportation Administration under provisions of the Surface Transportation Assistance Act of 1982

Suggested Citation
Gordon J. Fielding, Mark. Yamarone and Marcy Jaffe (1987) Using UMTA Section 15 data for triennial reviews. Final Report CA-06-0213-3. Washington, D.C. : Springfield, Va.: U.S. Dept. of Transportation, Urban Mass Transportation Administration, Office of Grants Management ; Available through the National Technical Information Service. Available at: https://catalog.hathitrust.org/Record/102497535.

conference paper

An analysis of train emissions and their health impacts in California's alameda corridor

Proceedings of INFORMS, san diego, CA

Publication Date

October 1, 2009
Suggested Citation
J. Saphores, M. Sangkapichai, S. Ritchie, G. Lee, I. You and R. Ayala (2009) “An analysis of train emissions and their health impacts in California's alameda corridor”, in Proceedings of INFORMS, san diego, CA.