Estimating service related traffic demand from trip chain data

Kurzfassung

Commercial traffic constitutes a significant part of traffic. While on long distances goods traffic prevails, in metropolitan areas service related traffic (i.e. traffic resulting from services delivered to customers at home, offices, constructions sites etc.) takes the lead – and is growing. This kind of traffic is primarily passenger traffic, but for commercial reasons. Even though goods (e.g. tools) might be transported together with the person (agent, worker etc.), the major purpose of service trips is the movement of the person. It is common practice to forecast transport demand for private passenger traffic and goods traffic. Dedicated models for service traffic are still rare. This is not only due to the lacking recognition of the particularities of this special part of traffic among transport planners, it is also due to the complexity of analyzing and depicting service traffic. One characteristic of service traffic is that it consists of tours connecting sometimes more than one destination with the origin of the tour. Many trips are trips with commercial vehicles, registered by a company or organization, but also private vehicle owners use their cars for commercial trips. Because surveys can only collect information on trip chains for a sample population, a method is needed to derive the total demand from this sample. Surveys on private and commercial vehicles used for service trips are particularly useful for this purpose. This article introduces such a methodology to extrapolate traffic demand from trip chain data. It is not only applicable to service traffic, but to all tour based traffic.