Accessibility is a key concept in transport and urban planning. The key aims of transport policies, not only at the urban level but also at the supra-national (for example, European Union), national and regional level, are to improve accessibility. But what is accessibility? Several policy documents do not specify what they mean by accessibility, but only through specific aims or policy measures does it becomes clear what they mean. For example the policies may aim to reduce congestion on roads. We think it is important to define accessibility, to avoid miscommunication and to make explicit what policies could, or even should, focus on. Above we give the example of congestion, an important topic in many policy plans, and we do not want to argue that reducing congestion is not important, but in this chapter we adopt a broader perspective. Following our previous work we define accessibility as ‘the extent to which land-use and transport systems enable (groups of) individuals to reach activities or destinations by means of a (combination of) transport mode(s)’@en

In current practice, transportation planning often ignores the effects of major transportation improvements on land use and the distribution of land use activities, which might affect the accessibility impacts and economic efficiency of the transportation investment strategies. In this paper, we describe the model specification and application of the land use transport interaction model TIGRIS XL for the Netherlands. The TIGRIS XL land-use and transport interaction model can internationally be positioned among the recursive or quasi-dynamic land-use and transport interaction models. The National Model System, the main transport model used in Dutch national transport policy making and evaluation, is fully integrated in the modeling framework. Accessibility modeling and evaluation are sis aggregated and fully consistent, which is not common in accessibility modeling research. Logsum accessibility measures estimated by the transport model are used as explanatory variables for the residential and firm location modules and as indicators in policy evaluations, expressing accessibility benefits expressed in monetary terms. Modeling results indicate that accessibility changes from transport investments in the Netherlands have a significant but modest positive influence on the location choice of residents and firms. This is probably mainly due to the spatial structure and already dense and well developed transport networks, and the large influence of national, regional and local governments on the Dutch land use markets.@en

We examine the accessibility benefits associated with some land-use policy strategies for the Netherlands that anticipate on expected climate change. A disaggregate logsum accessibility measure using the Dutch national land-use/transport interaction model TIGRIS XL is used to compute changes in consumer surplus. The measure provides an elegant and convenient solution to measure the full accessibility benefits from land-use and/or transport policies, when discrete choice travel-demand models are available that already produce logsums. It accounts for both changes in generalised transport costs and changes in destination utility, and is thus capable of providing the accessibility benefits from changes in the distribution of activities, due to transport or land-use policies. The case study shows that logsum accessibility benefits from land-use policy strategies can be quite large compared to investment programmes for road and public transport infrastructure, largely due to changes in trip production and destination utility, which are not measured in the standard rule-of-half benefit measure.@en