Implications of modeling commercial vehicle empty trips are discussed, a theoretical derivation for parameter estimation is provided, and insight is given into the order of magnitude of estimation errors because of the improper modeling of commercial vehicle empty trips. A set of relatively simple cases was designed to illustrate the most important implications. Also addressed are estimation errors from using naïve approaches to compensate for the lack of explicit modeling of empty trips and the errors associated with more advanced empty trip models. In the simplest simulation, directional errors for a basic complementary model were from three to six times fewer than those for the naïve models. In the more complex case, a more sophisticated complementary model performed slightly better than the basic model and both complementary models were considerably better than the naïve approaches. The directional errors for the naïve models were four to seven times greater than those for the complementary models. Moreover, an analysis of the statistical distributions of the errors indicated that the complementary models had higher probabilities of producing accurate results, whereas the naïve approaches had higher probabilities of producing very large errors. These analyses indicate that the naïve approaches translate into significant errors in directional-traffic estimates. For that reason, their use should be discontinued in favor of the more advanced models presented.

Land-use planning and policymaking is central to how communities manage their economic activity and the social and environmental impacts these activities produce. Because of this central role, enhancing land-use practices to better incorporate the needs and impacts of freight activity has strong potential to improve the efficiency of their associated supply chains. This paper summarizes the key findings of the NCFRP 08-111 project on “Freight-Efficient Land Uses (FELUs)”, probably the most comprehensive research project to date aimed at designing policy procedures to foster land-uses that minimize the private and external costs associated with the production, transportation, and consumption of goods. As part of the paper, the authors define freight efficient land-uses, identify the principles that should guide the process towards FELUs, outline the process to develop FELU plans and programs, propose to analyze the freight efficiency of current and future land uses in their jurisdictions, and identify complementary initiatives (both land-use and transportation related) that could help mitigate the negative impacts on local communities. The authors discuss three illustrative cases that provide evidence on how land-use decisions produce unintended effects on local communities. The paper explains how decision makers can carefully consider the FELU principles in their planning and avoid or mitigate such negative results.

The economic and financial feasibility of heavy-truck toll lanes was analyzed. This research expanded the line of inquiry of previous researchers by analyzing toll lanes for exclusive use by heavy trucks (i.e., large size and capacity). Implementation of such a toll system was studied relative to productivity changes, toll-lane fees, users' travel time and vehicle operating cost savings, and impact on infrastructure costs. The economic benefits were estimated using the Highway Design and Maintenance Standards Model developed by the World Bank. The analyses, complemented with sensitivity analyses of key variables, indicate that heavy-truck lanes are economically and financially viable.

The location of joint distribution center (JDC) is of great importance in urban freight system. This work aims to minimize the total cost, including the fixed cost, the transportation cost, and the penalty cost for the missed deliveries, considering the joint distribution willingness (JDW) of restaurant and the coverage radius of JDC. The integer programming model is formulated to select the optimal location of JDC and opens no more than k-JDCs. To solve the problem, an improved K-means (I-K-means) algorithm combining local search with penalty is proposed. The delivery problems obtained by freight survey from 114 restaurants in Beijing, China are taken as a case study. The formulation in this paper can reduce the cost of deliveries in restaurant industry, decrease the number of freight vehicles on road, and promote the joint distribution mode in urban freight system.

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