Deliveries to residential units: A rising form of freight transportation in the U.S.

As a result of the rapid growth of online shopping, more goods and services are delivered directly to residential units. The door-to-door deliveries improve residents' accessibility to retail sector, and at the same time create truck delivery trips. However, partially due to the data limitation, most existing freight research focuses on freight trips generated by business establishments. Little is known about freight trips generated by residential units. As a growing number of urban areas are pushing for dense and mixed development, it is necessary to understand the pattern of truck freight trips directly generated by residential units. This paper uses the U.S. National Household Travel Survey (NHTS) data to investigate the freight trips generated by residential units. The 2009 NHTS provides accurate, comprehensive and timely information on trips, land use, household characteristics and social economic factors. It is the first time that the NHTS data is used to estimate freight trips. A binary choice model and a right-censored negative binomial model are used to identify the impacts of person-related, household-related, and regional-specific variables on home delivery frequency. A case study for the New York State Capital District is then presented. The estimated freight trips generated by residential units are also compared to the freight trips generated by business establishments. Results, although still preliminary and subject to uncertainty, indicate that freight trips generated by residential units have comparable magnitude as the freight trips generated by businesses. Such a study will supplement city logistics studies that traditionally focus on business behavior, helping reconstruct a complete picture of the freight activities in urban areas.