Accessibility is usually evaluated using indicators calculated from spatial data. However, perceived accessibility, defined as the perceived potential to participate in spatially dispersed opportunities, is often poorly reflected by these calculated measures. This paper sets out to explain the mechanisms that lead to these mismatches. A conceptual model is constructed to establish what factors shape perceived accessibility. A schematic framework shows that mismatches between a calculated indicator and perceptions can stem from inaccuracies in awareness as well as from inaccuracies in the measure if the measure fails to take account of the subjective evaluations of accessibility components. When evaluating the performance of land-use and transport system configurations, calculated measures based on spatial and transport data only serve as proxies for how accessibility is actually experienced. This paper argues that bringing perceived accessibility to the fore of accessibility-based planning, by acknowledging and evaluating potential mismatches with calculated accessibility indicators, will advance the evolution from mobility-based to accessibility-based planning.

In this paper we explore the possible impacts of a distance- and emission-class based truck charge in The Netherlands. Earlier studies suggest that shifts may occur towards heavy vehicles, due to the relative inefficiency of lighter vehicles types. However, these studies have not taken into account the effects of changes in shipment size, as a response to pricing measures. Also, these studies have not considered emission-class dependent charges. Thirdly, no empirical disaggregate models or studies are available for the Netherlands for this problem. We present a discrete choice model for the joint choice of vehicle type and shipment size, estimated on a large dataset of disaggregate carrier freight trip data. The model explains variations in vehicle type choice for different transport purposes and contexts (e.g. commodity type, long-haul, urban transport, to/from logistic nodes). The analysis of emission based truck charging schemes shows that substitution towards low emission vehicles can be expected within the same vehicle class. It is also not likely that the truck charge will lead to a significant increase of shipment sizes or to substitution between vehicle types: a distance based truck charge increases transport costs but inventory costs restrain a shift to larger shipment sizes. This result points to a limited capability of supply chains to absorb transport cost increases by logistics re-organisation.