Combining Macro- and Microscopic Approaches to Model Commercial Transport Demand in an Urban Area

Abstract

Demand modeling of commercial transport has lagged behind private passenger demand modeling as a result of insufficient data sources and the complex types of movement. At a supra-regional level, commercial trips are usually conducted by heavy trucks. However, studies in urban areas show that only about 40% of all commercial trips are conducted by heavy vehicles, while the other 60% is conducted by light vehicles, indicating that this is not freight travel. Even though commercial transport has been somewhat regarded in recent research, most models focus on either freight trips or trips conducted to provide a service. However, for assessing policy sensitivity, all parts of commercial transport need to be considered.The model we present regards all aspects of commercial transport by assessing the parts separately. We distinguish between vehicles with variable and fixed daily. We further differentiate vehicles with fixed daily schedules into vehicles with short and long supply chains while focusing on the latter. To regard the entire supply chain of delivery vehicles we a combined macroscopic approach to obtain transit flows on a European level with a microscopic approach that is used to distribute the obtained packages of an urban area within said areas. The results of both the macroscopic and microscopic parts of the model are compared to traffic count data. The comparison of values show that the combination of macroscopic and microscopic model parts can model vehicles of commercial transport with a long supply chain, however, more attention should be regarded to the microscopic distribution.