ABSTRACT
Pre- or post-haulage (PPH) is an important part of intermodal freight chains and networks, as it substantially contributes to the door-do-door performance and costs. PPH easily stands for 50 per cent of the chain costs (both sides of the network). The new wave of transport sustainability research has clarified that PPH is also a crucial part of the environmental performance and external costs of chains and networks. The relevance of PPH stands in contrast to the limited amount of research devoted to this transport area. Central publications are Spasovic (1991), Transcare (1996), Nierat (1996), and the European research project Imprend (Buck et al., 1999). Finally there is a large range of affiliated operations research, which deals with strategies to collect and distribute freight in general.
Each of the sources is specific, and not sufficient to answer the central question of this chapter, namely: what are the cost quality ranges of PPH for the distance classes 5km, 25 km, 50km, and 100 km, taking account of alternative types of typical European operations? This question is important for the design of intermodal rail or barge networks.
With this background research in PPH was started at the Delft University of Technology. It consists of the working lines ‘overview model’ (spreadsheet), ‘development of (heuristic) planners’ (micro-simulation) (Aronson, Konings, and Kreutzberger, 2003), and ‘provision of field data’. The overview model distinguishes operational strategies, but is deterministic. Stochastic influences can be incorporated by implementing the results of simulations, such as from the heuristic planner. The latter is more sophisticated, but quite labour intensive, if it is to establish an overview of strategy results. The complexity of the planner 257also requires means to test its plausibility. The spreadsheet calculations are easy to understand, as the output can be directly traced to the initial and intermediate input. They can serve as plausibility instrument for the planner.
This chapter describes the three working lines, presents intermediate and final results of the overview model, amongst which answers to the central question, and shows how the heuristic planner tool can be used to validate assumptions about network unreliability.
