published journal article
Cordon tolling in a city with congested bridges
Economics of Transportation
Publication Date
December 1, 2014
Archives: Research Products
published journal article
Examining the Relationship Between Extreme Temperature, Microclimate Indicators, and Gestational Diabetes Mellitus in Pregnant Women Living in Southern California
Environmental Epidemiology
Publication Date
June 1, 2023
Author(s)
Anais Teyton, Yi Sun, John Molitor, Jiu-Chiuan Chen, David Sacks, Chantal Avila, Vicki Chiu, Jeff Slezak, Darios Getahun, Jun Wu, Tarik Benmarhnia
Abstract
Introduction: Few studies have assessed extreme temperatures’ impact on gestational diabetes mellitus (GDM). We examined the relation between GDM risk with weekly exposure to extreme high and low temperatures during the first 24 weeks of gestation and assessed potential effect modification by microclimate indicators. Methods: We utilized 2008–2018 data for pregnant women from Kaiser Permanente Southern California electronic health records. GDM screening occurred between 24 and 28 gestational weeks for most women using the Carpenter-Coustan criteria or the International Association of Diabetes and Pregnancy Study Groups criteria. Daily maximum, minimum, and mean temperature data were linked to participants’ residential address. We utilized distributed lag models, which assessed the lag from the first to the corresponding week, with logistic regression models to examine the exposure-lag-response associations between the 12 weekly extreme temperature exposures and GDM risk. We used the relative risk due to interaction (RERI) to estimate the additive modification of microclimate indicators on the relation between extreme temperature and GDM risk. Results: GDM risks increased with extreme low temperature during gestational weeks 20–-24 and with extreme high temperature at weeks 11–16. Microclimate indicators modified the influence of extreme temperatures on GDM risk. For example, there were positive RERIs for high-temperature extremes and less greenness, and a negative RERI for low-temperature extremes and increased impervious surface percentage. Discussion: Susceptibility windows to extreme temperatures during pregnancy were observed. Modifiable microclimate indicators were identified that may attenuate temperature exposures during these windows, which could in turn reduce the health burden from GDM.
Suggested Citation
Anais Teyton, Yi Sun, John Molitor, Jiu-Chiuan Chen, David Sacks, Chantal Avila, Vicki Chiu, Jeff Slezak, Darios Getahun, Jun Wu and Tarik Benmarhnia (2023) “Examining the Relationship Between Extreme Temperature, Microclimate Indicators, and Gestational Diabetes Mellitus in Pregnant Women Living in Southern California”, Environmental Epidemiology, 7(3), p. e252. Available at: 10.1097/EE9.0000000000000252. published journal article
Guest editors' introduction: Secure automotive systems
IEEE DESIGN & TEST
Publication Date
January 1, 2019
Author(s)
Sandip Ray, Ahmad-Reza Sadeghi, Mohammad Al Faruque
Suggested Citation
Sandip Ray, Ahmad-Reza Sadeghi and Mohammad Al Faruque (2019) “Guest editors' introduction: Secure automotive systems”, IEEE DESIGN & TEST, 36(6), pp. 5–6. Available at: 10.1109/MDAT.2019.2944085.
working paper
Did the 65 mph Speed Limit Save Lives?
Abstract
In 1987, most states raised the speed limit from 55 to 65 mph on portions of their rural interstate highways. There was intense debate about the increase, and numerous evaluations were conducted afterwards. These evaluations share a common problem: they only measure the local effects of the change. But the change must be judged by its system-wide effects. In particular, the new 65 mph limit allowed the state highway patrols to shift their resources from speed enforcement on the interstates to other safety activities and other highways — a shift many highway patrol chiefs had argued for. If the chiefs were correct, the new allocation of patrol resources should lead to a reduction in statewide fatality rates. Similarly, the change to drive faster on the interstates should attract drivers away from other, more dangerous roads, again generating system-wide consequences. This study measures these changes and obtains surprising results. We find that the 65 mph limit reduced statewide fatality rates by 3.4% to 5.1%, holding constant the effects of long-term trend, driving exposure, seat belt laws, and economic factors.
Suggested Citation
Charles Lave and Patrick Elias (1994) Did the 65 mph Speed Limit Save Lives?. Working Paper UCI-ITS-WP-95-5, UCTC 69. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/0z88b38t.Related Publications
working paper |
Dec 1994
Hazard Models of Changing Household Demographics
working paper |
Sep 1994
Population and Employment Densities: Structure and Change
working paper |
Oct 1993
Ameliorating Congestion by Income Redistribution
working paper |
Jan 1997
Economics and Urban Transportation Policy in the United States
book/book chapter |
Oct 1998
Project Evaluation
conference paper
Understanding the Internet-Wide Vulnerability Landscape for ROS-based Robotic Vehicles
Proceedings Symposium on Vehicle Security & Privacy
Publication Date
January 1, 2024
Author(s)
Wentao Chen, Sam Der, Yunpeng Luo, Fayzah Alshammari, Qi Alfred Chen
Suggested Citation
Wentao Chen, Sam Der, Yunpeng Luo, Fayzah Alshammari and Qi Alfred Chen (2024) “Understanding the Internet-Wide Vulnerability Landscape for ROS-based Robotic Vehicles”, in Proceedings Symposium on Vehicle Security & Privacy. Symposium on Vehicle Security & Privacy, San Diego, CA, USA: Internet Society. Available at: 10.14722/vehiclesec.2024.23018. conference paper
Dynamic simulation-assignment methodology to evaluate in-vehicle information strategies in urban traffic networks
1990 winter simulation conference proceedings
Publication Date
January 1, 1990
Author(s)
R. (Jay) Jayakrishnan, Hani Mahmassani
Suggested Citation
R. Jayakrishnan and H.S. Mahmassani (1990) “Dynamic simulation-assignment methodology to evaluate in-vehicle information strategies in urban traffic networks”, in 1990 winter simulation conference proceedings. IEEE, pp. 763–769. Available at: 10.1109/wsc.1990.129611. published journal article
Dimensions of anger Reactions-Revised (DAR-R): Validation of a brief anger measure in Australia and Spain
Journal of Clinical Psychology
Publication Date
February 1, 2019
Author(s)
Lee Kannis-Dymand, José M. Salguero, Juan Ramos-Cejudo, Raymond Novaco
Suggested Citation
Lee Kannis-Dymand, José M. Salguero, Juan Ramos-Cejudo and Raymond W. Novaco (2019) “Dimensions of anger Reactions-Revised (DAR-R): Validation of a brief anger measure in Australia and Spain”, Journal of Clinical Psychology, 75(7), pp. 1233–1248. Available at: 10.1002/jclp.22757. working paper
A Simultaneous Dynamic Travel and Activities Time Allocation Model
Publication Date
September 1, 1989
Associated Project
Author(s)
Leo J. G. van Wissen, Henk J. Meurs, Thomas Golob
Working Paper
UCI-ITS-WP-89-10, UCI-ITS-AS-WP-89-2
Areas of Expertise
Abstract
The model developed and estimated empirically concerns of the allocation of time to out-of-home activities and travel. This model has three important characteristics. First, the model is multivariate because there are interdependencies among time usages for different activities. The joint distribution of all relevant out-of-home activity times has to be taken into account. Second, travel is treated as a derived demand. The level of travel is the result of the spatial activity behaviour of the individual. Of course, the exact relation between activity performance and travel demand is highly complex. The spatial dispersion and quality of activity locations and the scheduling of activities by individuals are both important elements that need to be studied in order to predict total travel demand from a given activity pattern. Here a much simpler approach is taken. It is assumed that total travel time expenditure over a certain time period (i.e. one week) for an activity is proportional to the total amount of time engaged in that activity.The third main feature of the model is its longitudinal character. Longitudinal data have a number of advantages over cross-sectional data (see e.g. Hensher, 1985; Davies and Pickles, 1985; Kitamura, 1989; van Wissen and Meurs, 1989). from a statistical point of view it allows the estimation of model· parameters conditional on un-observed stationary characteristics and individual taste variations. From a theoretical point of view longitudinal data are necessary in order to identify and estimate dynamic processes. In this study only the statistical advantages of longitudinal data will be used. This paper is organized as follows. In section two an overview is given-of earlier related work on the allocation of time and the travel consequences. In section three the model methodology will be presented. Next, in section four, the data will be described briefly. Section five contains the empirical results of the model estimation. These results are evaluated and some conclusions are drawn in section six.
Suggested Citation
Leo J.G. van Wissen, Henk J. Meurs and Thomas F. Golob (1989) A Simultaneous Dynamic Travel and Activities Time Allocation Model. Working Paper UCI-ITS-WP-89-10, UCI-ITS-AS-WP-89-2. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/6cv0x6w9.Related Publications
working paper |
Jun 1991
Home Environment Consequences of Commute Travel Impedance
working paper |
Jun 1989
Aggression on Roadways
working paper |
Nov 1991
Structural Models of the Effects of the Commute Trip on Travel and Activity Participation
working paper |
Nov 1988
Simultaneous Equation Systems Involving Binary Choice Variables
working paper |
Sep 1991
Court Intervention, The Consent Decree, and The Century Freeway
published journal article
Integrating demand forecasts into the operational strategies of shared automated vehicle mobility services: spatial resolution impacts
Transportation Letters
Publication Date
November 25, 2020
Author(s)
Michael Hyland, Florian Dandl, Klaus Bogenberger, Hani Mahmassani
Abstract
This study aims to evaluate and quantify the impact of demand forecast spatial resolution on the operational performance of a shared-use automated vehicle (AV) mobility service (SAMS) fleet. To perform the evaluation, this study employs an agent-based modeling framework that includes user requests, AVs, and an SAMS fleet controller. In the simulation, an SAMS fleet controller dynamically assigns AVs to on-demand user requests and repositions empty AVs throughout the service region to serve expected future demand requests. The fleet controller uses an offline demand forecast model and an online optimization model that jointly assigns AVs to users and repositioning trips. Results indicate that despite demand forecast quality decreasing at higher spatial resolutions, the operational efficiency of the SAMS fleet increases with higher spatial resolution forecasts (i.e. smaller subareas). Results also indicate that there is a significant operational value associated with improving short-term demand forecasts at high spatial resolutions.
Suggested Citation
Michael Hyland, Florian Dandl, Klaus Bogenberger and Hani Mahmassani (2020) “Integrating demand forecasts into the operational strategies of shared automated vehicle mobility services: spatial resolution impacts”, Transportation Letters, 12(10), pp. 671–676. Available at: 10.1080/19427867.2019.1691297. published journal article
A spatio-temporal decomposition based deep neural network for time series forecasting
Applied Soft Computing
Publication Date
February 1, 2020