A new generation of advanced power technologies is rapidly emerging based on the concept of distributed generation (DG) and, more broadly, distributed energy resources (DER). DER systems have the potential to dramatically increase the efficiency of end-user energy use, particularly when coupled with the utilization of waste heat for local heating and/or cooling needs. At the same time, DER systems can help to reduce the need for siting large power plants and transmission lines. Furthermore, DER systems can also offer environmental benefits through installation of clean technologies such as...
The COVID pandemic has accelerated the growth of ecommerce and reshaped shopping patterns, which in turn impacts trip-making and vehicle miles traveled. The objectives of this study are to define shopping styles and quantify their prevalence in the population, investigate the impact of the pandemic on shopping style transition, understand the generational heterogeneity and other factors that influence shopping styles, and comment on the potential impact of the pandemic on long-term shopping behavior. Two months after the initial shutdown (May/June 2021), we collected ecommerce behavioral...
A significant portion of the population stayed, and continue to stay, at home due to the COVID-19 pandemic. With more people staying home, online shopping increased along with trips related to pickups and deliveries. To gain a better understanding of the change in retail purchases and related travel, UC Berkeley researchers compared pre-pandemic shopping to pandemic-related shifts in consumer purchases in the greater Sacramento area for nine types of essential and non-essential commodities (e.g., groceries, meals, clothing, paper products, cleaning supplies). In May 2020, the research team...
The rapid expansion of trade and the intense pace of the economic activities of ports pose numerous social and environmental challenges, and thus put port hinterland regions at risk and challenge traditional port business models. Few studies have examined the conceptual and empirical issues involved in improving port sustainability, although port sustainability issues have recently been discussed with some urgency in the goods movement sector. This paper sets out a conceptual model of port sustainability, presents and examines multiple concepts of supply chains surrounding port activity,...
As California grows, increased travel from more households, business activity, and goods movement will surely increase greenhouse gas emissions, lead to more congestion and air pollution, and damage ecosystems and neighborhoods—unless we change the basics of travel in California. We need to take action now to deliver a sustainable transportation system that provides the mobility and accessibility necessary for a prosperous economy, and to find ways of doing so that also assure a healthy environment, social equity, and a high quality of life. Here are some ideas for managing, improving, and...
This paper studies the costs involved in distributing items from a warehouse or depot to randomly scattered customers on a day-to-day basis. Two trade-offs are explored simultaneously. The first one arises because by accumulating large inventories at the depot it is possible to build more efficient distribution tours. This trade-off has already been explored for both distribution of goods (Burns et al., 1983) and passengers (Daganzo et al., 1977; Hendrickson, 1978). Another tradeoff, which involves the length of individual vehicle tours (...
The purpose of this paper is to develop a simple formula to predict the distance traveled by fleets of vehicles in physical distribution problems involving a depot and its area of influence. Since the transportation cost of operating a break-bulk terminal (or a warehouse) is intimately related to the distance traveled, the availability of such a simple formula should facilitate the study of more complex logistics problems. A simple manual dispatching strategy intended to mimic what dispatchers do, but simple enough to admit analytical modeling is presented. Since the formulas agree rather...
The amount of freight that can be fit on a vehicle depends on the vehicle's weight capacity and volume capacity. In this paper mathematical equations are developed for evaluating the impact of weight capacity and volume capacity on total vehicle-miles. It is shown that the number of vehicle loads needed to carry a large amount of material is minimized when all vehicles are filled to the same capacity constraint. This is accomplished by mixing light items with heavy items in vehicle loads. Following this policy can reduce the number of vehicle loads and vehicle-miles. Under ideal...
