Measuring In-betweenness: Identifying Interplaces in Dutch and Belgian Metropolitan Regions

Wander Demuynck1,2, Michiel Van Meeteren2, Evert Meijers2& Ben Derudder1 1KU Leuven, Belgium 2Utrecht University, The Netherlands MEASURING IN-BETWEENNESS Identifying interplaces in Belgian and Dutch metropolitan regions Main Dutch municipalities AAmsterdam Al Alkmaar Ap Apeldoorn Ar Arnhem BBreda BoZ Bergen-opZoom DDeventer Do Dordrecht DB Den Bosch EEindhoven En Enschede GGroningen NNijmegen MMaastricht R Roosendaal T Tilburg TH The Hague ZZwolle Main Belgian municipalities AAntwerp Aa Aalst Ar Arlon B Brussels Br Bruges C Charleroi CX Campine Axis E Eupen G Ghent Ge Genk H Halle Ha Hasselt KKortrijk L Liège Le Leuven MMons MeF Marche-enFamenne NNamur R Roeselare SN Sint-Niklaas TTurnhout To Tournai V Verviers W Wavre YYpres Belgian interplaces aAsse bBraine l’Alleud d Dendermonde nNivelles oOttigniesLouvainla-Neuve ov Overijse pPuurs-SintAmands vVilvoorde zZaventem Dutch interplaces aAmstelveen al Almere am Amersfoort ar Alphen aan den Rijn hHaarlem ha Haarlemmermeer har Harderwijk hi Hilversum gGouda wWoerden zZaanstad Metropolitan regions 1Randstad 2Brabant Urban Row 3Flemish Diamond 4Walloon Triangle MEASURING IN-BETWEENNESS Identifying interplaces in Belgian and Dutch metropolitan regions Wander Demuynck1,2, Michiel Van Meeteren2, Evert Meijers2& Ben Derudder1 1KU Leuven, Belgium 2Utrecht University, The Netherlands THE AIM OF THIS RESEARCH is to present a method that consistently identifies interplaces on the basis of commuting flows and highlight how this method can be used to get a better understanding of the structure of metropolitan regions by comparing the cases of The Netherlands and Belgium. Metropolitan regions are shaped not only by core cities but also by a class of overlooked localities — interplaces — that are locally central, outwardly networked and function as hinges across scales. This study develops a reproducible method to identify interplaces from municipal commuting flows and compares outcomes across the two contrasting metropolitan systems of The Netherlands and Belgium. METHODOLOGICALLY, our approach detects interplaces similar to those found in other research [5][6][10][11], albeit in a much more comprehensive fashion. It provides a solid basis for consistent interplace-identification. [1] Phelps, N. A. (2017). Interplaces: An Economic Geography of the Inter-urban and International Economies. Oxford University Press. [2] Demuynck, W., Derudder, B., Meijers, E., & van Meeteren, M. (2025). Between suburb and city: Conceptualising interplaces. Urban Studies, 00420980251376979. [3] Sweet, M., & Scott, D. M. (2024). What might working from home mean for the geography of work and commuting in the Greater Golden Horseshoe, Canada? Urban Studies, 61(3), 567-588. [4] Cardoso, R., & Meijers, E. (2021). Metropolisation: The winding road toward the citification of the region. Urban Geography, 42(1), 1–20. [5] Poorthuis, A., & Van Meeteren, M. (2021). Containment and Connectivity in Dutch Urban Systems: A Network-Analytical Operationalisation of the Three-Systems Model. Tijdschrift Voor Economische En Sociale Geografie,112(4), 387–403.[6] Halleux, J.-M., Treffer, M., & Maldague, H. (2021). Polycentricity and multipolarisation of urban outskirts: From polycentric urban region to megapolitan region. Cities, 119, 103390. [7] Van Meeteren M., Neal Z., & Derudder B. (2016). Disentangling agglomeration and network externalities: A conceptual typology. Papers in Regional Science, 95(1), 61–80. [8] Traag, V. A., Waltman, L., & van Eck, N. J. (2019). From Louvain to Leiden: Guaranteeing well-connected communities. Scientific Reports,9(1), Article 1. [9] Verhetsel, A., Beckers, J., & De Meyere, M. (2018). Assessing Daily Urban Systems: A Heterogeneous Commuting Network Approach. Networks and Spatial Economics, 18(3), 633–656. [10] Limtanakool, N., Schwanen, T., & Dijst, M. (2009). Developments in the Dutch Urban System on the Basis of Flows. Regional Studies, 43(2), 179–196. [11] Van Meeteren, M., Boussauw, K., Derudder, B., & Witlox, F. (2016). Flemish Diamond or ABC-Axis? The spatial structure of the Belgian metropolitan area. European Planning Studies, 24(5), 974–995. UNFORTUNATELY, interplaces have attracted only modest analytical engagement [5][6] because they are a seemingly heterogeneous category and because they are ‘in-between’ both as places, in networks and across scales. This makes them hard to consistently identify. INTERPLACES MATTER because they are attractive places of residence and employment compared to inner cities and suburbs (green space, public transport access, urban character, lower rents) [3]. Their growth as complementary places leads to a more integrated metropolitan regions [4]. INTERPLACES ARE the places in metropolitan regions that are situated in between multiple cities, have a function that is neither fully urban nor suburban. This can include a variety of settlements (small towns, post-suburban edge cities, industrial satellite cities, planned growth centres, etc.) [1][2]. Urban field vs. urban network Conclusion Results Most Dutch interplaces are situated in (the North Wing of) the Randstad, confirming that it is its most polycentric part [10] … Intermediate subcentres lack the topological in-betweenness of interplaces and are situated along the edges of the main metropolitan regions Networked suburbs lack the centrality of interplaces but send commuters to multiple cities, subcentres and interplaces Interplaces –so what? Spatial phenomena in metropolitan regions (e.g. commuting flows) typically follow field distributions yet they are often operationalized as networks for the sake of analysis [7]. Network approaches typically overlook interplaces, and this: •because they don’t qualify as full ‘nodes’ in the network yet function as important subcentres (place in-betweenness) [2] •despite them being highly important in connecting multiple places into a coherent metropolitan region (topological inbetweenness) [1] •because they don’t align with yet function as hinges across conventional analytical scales (scalar in-betweenness) [6] Helmond is the only Dutch interplace not situated in the Randstad, but along the (envisioned) Brabant Urban Row Intermediate cities are often found in between other cities or on infrastructural crossroads Most Belgian interplaces align along the Antwerp– Brussels–Charleroi axis, The Netherlands and Belgium •Similarities: highly urbanized; similar size and economic structure; Randstad and Flemish Diamond frequently analysed through city-centric ‘polycentric network’ frameworks. •Differences: planning histories and morphological structure. → Comparison: similar or different functional patterns when viewed from the perspective of interplaces? Research grant 11P8V24N Collapsed into a single city-region Density peaks of different intensity Our method accounts for and measures in-betweenness: 1) Detecting coherent labour market areas across multiple scales using community detection [8] 2) Calculating the centrality within and topological embeddedness beyond the labour market area at each scale and for each municipality. 3) Constructing a typology of municipalities [9] based on their highest place centrality and topological in-betweenness score Place and topological in-betweenness are the basis of the typology of places Method typical suburb interplace! typical city Case study & data Some examples Data Municipality-level commuting flows in 2021; separate data & analyses for The Netherlands (CBS) and Belgium (Statbel). … yet the metropolitan region also extends further eastward towards places like Amersfoort and Harderwijk… … and further south on the infrastructural crossroads between the G4 (e.g. Gouda). The main cities are either isolated or intermediately networked due to their self-reliance Most other municipalities are abundant in the more peripheral areas of the national urban system Mechelen is the most notable example of a networked city as it is both externally connected and very central despite the influence of nearby Antwerp & Brussels indicating that envisioned polycentric regions like the ‘Flemish Diamond’ and ‘Walloon Triangle’ are structured around limited functional corridors rather than the entire region [11]. Scalar in-betweenness derived from position on map Despite their contrasting spatial morphologies and planning traditions, the Belgian and Dutch labor markets exhibit strikingly similar functional geographies when viewed through their interplaces. In both countries, these moderately central yet highly connected municipalities cluster along corridors within their main metropolitan regions the Randstad and the Flemish Diamond/Walloon Triangle. FUTURE RESEARCH can expand the geographical or longitudinal scope of this research, start from smaller basic spatial units to avoid issues related to the MAUP or apply the method to other types of functional flows (e.g. business transactions) or governance and cultural relations between places. COMPARATIVELY, Dutch and Belgian functional geographies are much more similar than their differing morphological structures would suggest. EMPIRICALLY, interplaces are shown to be widespread and structurally significant in metropolitan labor markets by functioning as emerging local subcenters and linking major centers through commuting flows. A wide variety of places (residential towns, post-suburban centers, former industrial cities, planned towns, etc.) can qualify as interplaces, underscoring the need to approach them comprehensively instead of as separate categories. References