Accessibility Impacts of Alternative Urbanization Strategies in the Netherlands
Barry Zondag, Significance
This paper presents the accessibility impacts of alternative urban strategies for urban regions in the Netherlands . These urban strategies result in large accessibility benefits consisting of changes in the proximity of activities and travel times.
The Ministry of Infrastructure and Environment of the Netherlands has launched a new policy program to explore a wider approach to improve accessibility. The program should avoid a single focus on infrastructure investments and advocates an integrated regional approach, to be worked out by national, regional and local stakeholders, including multi-modal, ICT and land-use strategies. This study was commissioned by the Ministry of Infrastructure and Environment to calculate the accessibility impacts of alternative urban strategies.
The impacts of the various land use alternatives are calculated by applying the TIGRIS XL model, a land use and transport interaction model for the Netherlands. In the paper we discuss the impacts on both network accessibility, by using a congestion indicator, as well as geographical accessibility, including both travel times and proximity of activities. A geographic-economic accessibility indicator, using the micro economic utility functions in the modelling, is used to calculate the accessibility benefits in monetary terms. These accessibility benefits result of changes in travel times and costs as well as in changes in the proximity of activities.
Eight different land use variants have been defined in the study and were compared with a reference scenario for the land use developments up to 2040. The land use variants vary between more or less concentration in urban or suburban areas and are implemented at a municipality or at a neighborhood level by type of neighborhoods (e.g. urban center with high densities or residential green and low density neighborhoods). In two variant the land use developments take advantage of existing infrastructure and in these variants developments are oriented at well accessible transit or high way locations.
The reference scenario assumes a housing demand of around one million houses, in addition to the existing housing stock of 7.2 million houses, in the period up to 2040. The alternative land use variants vary in the location choice of around 20% of this housing program, or 200 thousand houses. The alternatives were implemented at a regional scale for all the 22 urban regions in the Netherlands as identified by the Statistics Netherlands. This regional approach means that the population for each region is in all variants similar to the reference scenario and the population figures differ at the level of zones within a region. All the variants assume that there are no changes in the transport system in comparison with the reference scenario.
The land use variants have impact on congestion levels and congestion figures at a national level, compared to the reference case, vary between plus 9%, for suburban oriented variants and minus 7% for the combi variant consisting of a higher urban densification and developments oriented at well accessible public transport locations. The differences in accessibility benefits, including proximity impacts as well, are very substantial and the welfare benefits vary between -350 million Euro, for the green residential variant, and plus 522 million Euro for the combi variant of densification and public transport. These welfare benefits are yearly benefits calculated for 2040 and expressed in 2010 Euro’s.
Based on these findings several recommendations were proposed for the Ministry of Infrastructure and Environment. Main recommendations are:
• A regional robustness indicator is proposed to test the sensitivity of bottlenecks, like congestion, within regions for alternative land use patterns. This information should be part of the discussions between the national and regional government on infrastructure spending to solve bottlenecks in the road infrastructure;
• Use wider geographically based accessibility indicators as land use variants have a larger potential to improve the proximity of activities and therewith the accessibility of regions. Network based accessibility indicators do not include these benefits and the use of wider geographical indicators is needed to avoid a single focus on network measures. In the evaluation phase the wider accessibility benefits should be part of a cost benefit analysis including among others investment and maintenance costs, open space, public transport budgets, etc.
Association for European Transport