conference paper
published journal article
The current methods of franchising highways in America have been devised in haste and can be improved upon. The project should first be defined and then guided through environmental approval. The authors suggest that this should be done by an independent state body endowed with the mission of franchising highways. The project could then be auctioned, and the winning bidder would complete the final design and then finance, construct and operate the highway.
conference paper
In the research presented here, an attempt is made to analyze the entire daily activity pattern simultaneously in terms of its space, time, and activity category dimensions. The focus of the research is on developing procedures for the dynamic analysis of possible changes in activity patterns that may result from or lead to changes in the characteristics of the household. The intent is to trace the daily activity patterns of groups of travelers that have undergone significant change during multiple points in time, in a manner that will shed some light on both the nature and extent of associated changes in travel behavior. To check on the reliability of the modeling process and to understand its peculiarities, complementary analyses of pattern attributes, and time-series analyses of patterns were performed on the same data set. Results from these complementary analyses are briefly outlined here, and it is hoped that these results aid in placing the present approach in the perspective of the rich legacy of previous work.
conference paper
Alternative fuel adoption by heavy-duty vehicle (HDV) fleets can bring substantial benefits to both current local communities and future generations by reducing air pollutants and greenhouse gas emissions. A better understanding of HDV fleet operator perspectives towards alternative fuels can serve as the basis for developing effective policy suggestions that aim to accelerate the diffusion of these innovative technologies throughout the entire vehicle market. This study attempts to identify the factors that have influenced the decision for alternative fuel adoption or non-adoption made by HDV fleet operators in California. Through 18 in-depth qualitative interviews, a total of 25 adoption and 41 non-adoption cases were investigated across various alternative fuel options. Content analysis of the interview data yielded that the primary and most common factors comprised functional suitability, environmental consciousness, availability of vehicles, and regulations. Other important but less common factors were overall costs, vehicle purchase price, fuel price, fuel infrastructure, vehicle reliability and safety, contracts with municipalities, and financial incentives. Based on the key factors identified, testable propositions were developed and seven major hypotheses are presented. The study results help gain a better grasp of the demand-side aspects of alternative fuel adoption in the HDV sector in California.
published journal article
The impact of COVID-19 in the relationship between consumer-facing businesses and health and well-being remains understudied. In response, we utilized mixed methods to examine the perceived psychological benefits of urban parks and consumer-facing businesses among students from the University of California, Irvine before and after the COVID-19 lockdown. Overall, findings from photo-based close-ended questions indicated no significant disparity in perceived restorative quality, sentiment, and preference for urban third places before and after COVID-19 lockdowns. However, crowded third places exhibited a notable decline in sentiment and preference for third spaces following the COVID-19 lockdowns. Inductive content analysis of open-ended questions indicated a rise in visits to eating/drinking establishments and shops/stores post-COVID-19 lockdowns and a shift towards outdoor venues for activities. Findings support policy and planning efforts that promote healthy communities by maximizing the benefit of third places.
conference paper
published journal article
working paper
Set Covering problems find the optimal provision of service locations while guaranteeing an acceptable level of accessibility for every demand points in a given area. Other than reliance on static,exogenously-imposed accessibility measures, these problems either exclude substantive infrastructure-vehicle interactions or only include fragmented infrastructure-vehicle interactions related to the routing considerations of households seeking refueling service as a requirement of performing routine, daily activities. Here, we address this problem by coupling a Location-Routing Problem (LRP) that uses the set covering model as a location strategy to the Household Activity Pattern Problem (HAPP) as the mixed integer scheduling and routing model that optimizes households’ participation in out-of-home activities. The problem addressed includes multiple decision makers: the public/private sector as the service provider, and the collection of individual households that make their own routing decisions to perform a given set of “out-of-home activities” together with a visit to one of the service locations. A solution method that does not necessarily require the full information of the coverage matrix is developed to reduce the number of HAPPs that needs to be solved. The performance of the algorithm, as well as comparison of the results to the set covering model, is presented. Although the application is focused on identifying the optimal locations of Hydrogen Fuel Cell Vehicle (HFCV) refueling stations, this proposed formulation can be used as a facility location strategy for any service activity that is generally toured with other activities.
published journal article
published journal article