Trip Distribution

The emphasis of this research is on the analysis of commercial vehicle tours. Tours are disaggregated by their routing constraints. The generation of Vehicle Kilometers Traveled (VKT) by tour type is analytically modeled and analyzed. The relative influence of the number of stops per tour, tour duration, and time window constraints on VKT is discussed using an analytical framework. Multistop tours are shown to generate more VKT than direct deliveries even for equal payloads. Intuition about the impacts of network/logistics changes and policy implications on VKT is derived. Implications for the calibration of trip generation and distribution models are discussed. In the tour model, it is proven that the percentage of empty trips has no correlation with the efficiency of the tours regarding VKT generation. The shape of Trip Length Distributions (TLD) is discussed. It is shown that the average trip length and the TLD shape are strongly dependent on the tour type, distance from the depot/distribution center to the service area, density of stops, and number of stops per tour. Implications for data collection needs are analyzed