Estimation of the Origin-Destination Matrix for Trucks That Use Highways: A Case Study in Chile

Nowadays, freight transport is crucial in the functioning of cities worldwide. To dig further into the understanding of urban freight transport movements, in this research, we conducted a case study in which we estimated an origin-destination matrix for the trucks traveling on Autopista Central, one of Santiago de Chile’s most important urban highways. To do so, we used full real-world vehicle-by-vehicle information of freight vehicles’ movements along the highway. This data was collected from several toll collection gates equipped with free-flow and automatic vehicle identification technology. However, this data did not include any vehicle information before or after using the highway. To estimate the origins and destinations of these trips, we proposed a multisource methodology that used GPS information provided by SimpliRoute, a Chilean routing company. Nevertheless, this GPS data involved only a small subset of trucks that used the highway. In order to reduce the bias, we built a decision tree model for estimating the trips’ origin, whose input data was complemented by other public databases. Furthermore, we computed trip destinations using proportionality factors obtained from SimpliRoute data. Our results showed that most of the estimated origins belonged to outskirt municipalities, while the estimated destinations were mainly located in the downtown area. Our findings might help improve freight transport comprehension in the city, enabling the implementation of focused transport policies and investments to help mitigate negative externalities, such as congestion and pollution.

Extreme Winter Storms: Environmental Impacts of Public Utility Policies on Vulnerable Populations

Winter Storm Uri, one of the coldest in decades, brought snow and ice to Texas along with record subfreezing temperatures for 5 days February 13-17, 2021, and was followed by Winter Storm Viola, which brought more of the same February 18-19, 2021. Millions of Texans lost electricity and clean, running water for several days, which some suggest was due in part to a state-regulated energy market. Many Texas schools shut down for the entire week, as the death toll rose from these storms due to hypothermia and exposure, carbon monoxide poisoning, fire, drowning, and poor road conditions. Not only were COVID-19 vaccinations halted due to impassable roads but also Texas hospitals struggled to provide electricity and water pressure needed to perform life-saving medical treatments for their patients. The purpose of this article is to provide an overview of the historic winter storm event, identify vulnerable populations and key public health policies, and highlight the potential environmental public health risks associated with the storms.