working paper
Theories of relationships between land use and transportation, and the empirical research conducted to test these relationships are reviewed. Recent empirical research seldom supports theoretical expectations. These results are explained by the changes in urban structure that have occurred over the past three decades. The paper concludes with some suggestions for revising the theories to represent conditions in contemporary urban areas better.
working paper |
Sep 1991
working paper |
Aug 1990
working paper |
May 1990
working paper |
Jun 1991
published journal article
This paper generalizes the simple two-city work-from-home model of Brueckner et al. (2022) by adding a group of non-remote workers, who must live in the city where they work. The results show that the main qualitative conclusions of BKL regarding the intercity effects of WFH are unaffected by this modification, with WFH yielding the same aggregate population and employment changes in the two cities and the same house-price and wage effects as in the simpler model. Even though the aggregate population effects are the same, the population relocation of non-remote workers is in the opposite direction to that of remote workers, which matches the direction in BKL. These conclusions are useful because they establish the robustness of BKL’s highly parsimonious model. The paper also contains material surveying other theoretical research on WFH as well as empirical work in the area, including BKL’s empirical findings in support of their model.
working paper
A three-year experiment is underway in San Diego County, California that allows solo drivers to pay a fee to use “Express Lanes” i.e. carpool lanes to avoid an eighty-mile highly congested stretch of freeway. These lanes are also commonly referred to as High Occupancy Toll (HOT) Lanes. The facility has two reversible lanes in the freeway median separated by concrete barriers from the I-15 main lanes with access available only at the two end points. Tolls charged commonly range from $.50 to $4.00 per trip but in exceptionally congested conditions can go as high as $8. Fees charged can change dynamically every six minutes to reflect changing traffic in the carpool lanes. Changeable message signs post the price. The algorithm controlling the prices is adjusted to maintain free flow conditions in the carpool lanes at all times. Carpools of two or more persons retain free travel. Subscribers who chose to use the lanes are charged the posted toll using transponder technology and monthly credit-card billing. The opening hours for the Express Lanes are 5:45 to 9:15 a.m. inbound to San Diego and 3:00 – 7:00 p.m. outbound from San Diego.
published journal article
We consider the dynamic traveling repair problem in which requests with deadlines arrive through time on points in a metric space. Servers move from point to point at constant speed. The goal is to plan the motion of servers so that the maximum number of requests are met by their deadline. We consider a restricted version of the problem in which there is a single server and the length of time between the arrival of a request and its deadline is constant. We give upper bounds for the competitive ratio of two very natural algorithms as well as several lower bounds for any deterministic algorithm. Most of the results in this paper are expressed as a function of β, the diameter of the metric space. In particular, we prove that the upper bound given for one of the two algorithms is within a constant factor of the best possible competitive ratio.
conference paper |
Jan 2002
Phd Dissertation |
Jun 2001
published journal article
published journal article
MS Thesis
The purpose of this study is to provide a comprehensive analysis of UC Irvine affiliate transportation patterns and behavior. Through this analysis, recommendations on how to best promote more sustainable transportation on the UC Irvine campus was made to the two study sponsors, UCI Transportation and Distribution Services (TDS) and Anteater Express. With the assistance of TDS, an online survey was sent through a campus-wide email, and achieved overall sample size n = 2,034. Due to technical errors, freshmen did not receive the email. However, through the assistance of UCI Student Housing, surveys were sent to on-campus freshmen. Consequently, this still left out the off-campus freshmen and this exclusion impacted our analysis. Set aside from this limitation, the current study provided a framework, to the study sponsors, for an unprecedented comprehensive campus-wide transportation analysis at UC Irvine based on the study sponsor’s goals and objectives. Results indicate there is room for improving the use of alternative transportation for UCI affiliates who live within the City of Irvine in which UC Irvine is located. One recommendation pertains to increasing awareness of more sustainable transportation option and shedding light on transportation impacts early on such as during incoming student orientation and when students move out of the dorms and into local rental communities. That way when new UCI affiliates attempt to get acclimated to their new surroundings, with the early information, they can get the idea to explore alternative transportation as a potential way to be included within their daily life.
published journal article
BACKGROUND AND AIM[|]Urban biodiversity has a profound impact on human health that has not been thoroughly investigated. Little research exists regarding the associations between plant species richness and preterm birth (PTB). We aimed to examine the relationships between PTB and plant species richness, and the effect modifications by maternal characteristics, air pollution, ambient temperature, and the coronavirus disease (COVID-19) pandemic.[¤]METHOD[|]Clinical and sociodemographic data were obtained from Kaiser Permanente Southern California electronic health records in 2015–2021. PTB was defined as gestational age at birth less than 37 weeks. Maternal residential plant species diversity data were extracted from a wild vascular plant species diversity map across California urban areas at 5km resolution, and the maternal residential green space exposure data were assessed from satellite-based images (Normalized Difference Vegetation Index (NDVI) and land-cover green space). Multilevel logistic regressions were applied to examine the association between PTB and plant species diversity, after controlling for maternal age, race/ethnicity, education, and median household income. We also examined the effect modifications by maternal characteristics, air pollution, ambient temperature, and COVID pandemic (delivery before or during the pandemic) factors.[¤]RESULTS[|]In total, we included 302,266 births occurring between January 1, 2015, and December 31, 2021, with 21,421 (7.1%) PTB cases. Plant species richness in 2500m buffer showed a protective association with PTB (odds ratio [OR]: 0.980, 95% CI: 0.964, 0.996). The association persisted after further adjustments for NDVI and land-cover green space. The risk of PTB associated with plant species richness were significantly lower among mothers having a college degree, living in neighborhood with higher levels of O3 and average ambient temperature, and during the pandemic.[¤]CONCLUSIONS[|]This study found that maternal exposure to higher plant species diversity was associated with a decreased risk of PTB. Our findings suggest a complex interplay of sociodemographic and environmental factors influencing PTB risks.[¤]
book/book chapter
MS Thesis