Toepassing van het knoop-plaatsmodel in Vlaanderen

Het afstemmen van mobiliteit op ruimtelijke ordening en omgekeerd blijkt een moeilijke opgave in Vlaanderen. De wijze waarop beide beleidsdomeinen de voorbije decennia zijn vormgegeven staat haaks op de principes die naar aanloop van het Beleidsplan Ruimte Vlaanderen worden geagendeerd. Dit onderzoek focust op twee van deze ruimtelijke principes: ‘ontwikkelen op knooppunten van collectief vervoer’ en ‘ontwikkelen op basis van de bestaande voorzieningengraad’. Beide principes worden geassocieerd met het stedenbouwkundig principe Transit Oriented Development (TOD). Vertrekkende vanuit het knoop-plaatsmodel van Bertolini (1999) worden in dit onderzoek alle treinstations in het Vlaamse en Brusselse spoornetwerk onder de loep genomen. In het model wordt de bereikbaarheid van en naar het knooppunt en de centraliteit in het netwerk geconfronteerd met de nabijheid van verschillende types voorzieningen, inwoners- en tewerkstellings-dichtheden en andere aspecten van de ruimtelijke structuur. Een dergelijke analyse laat toe om het verband tussen beide dimensies op systematische wijze voor elk knooppunt te visualiseren en te onderzoeken, en om verschillende types stationsbuurten te onderscheiden met het oog op het formuleren van ontwikkelingskansen voor strategische verdichting langsheen knooppunten van collectief vervoer. De eerste resultaten uit dit onderzoek lijken de evenwichtsassumptie uit Bertolini’s knoop-plaatsmodel voor Vlaanderen te bevestigen. Het merendeel van de stations bevindt zich immers in de ‘gebalanceerde’ gebieden van het model. Na verdere algemene observaties voor het Vlaams en Brussels Hoofdstedelijke Gewest, worden enkele knopen die duidelijk afwijken van dit generieke verband in meer detail toegelicht. Een discussie waarin enkele randvoorwaarden tot succesvolle implementatie van TOD-ingrepen, bedenkingen ten aanzien van duurzaam transportbeleid en toekomstige onderzoekslijnen worden geschetst, sluit het geheel af

Meet & fly : sustainable transport academics and the elephant in the room

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The Effects of Urban Polycentricity on Particulate Matter Emissions From Vehicles: Evidence From 102 Chinese Cities

This article analyzes the impact of the level of urban polycentricity (UP) on particulate matter emissions from vehicles (PMV) across 102 prefecture-level cities in China between 2011 and 2015. We adopt a spatial panel modeling approach to our measures of UP and PMV, controlling for (possible) intervening effects such as population density and economic output. We observe an inverted U-shaped relationship between both measures: When UP is low, an increase in polycentricity is associated with higher levels of PMV; however, when UP reaches a certain threshold, the increase in polycentricity is associated with a reduction in PMV. We find a similar relationship between economic output and PMV and demonstrate how the effects of population density on PMV consist of two opposite processes that likely offset each other. Nonetheless, jointly, population density and UP have a significant effect on PMV. We use our results to discuss policy implications and identify avenues for further research

Investigating walking accessibility to recreational amenities for elderly people in Nanjing, China

Taking into account the rapidly aging demographic landscape in China, securing elderly’s right to participate in society has become an urgent challenge. Geographical access to urban amenities is known to influence social participation and integration. However, the application of accessibility analysis to elderly population in China has received little attention to date. This study examines the walking accessibility to recreational amenities for older adults in the Chinese context with an explicit focus on equity. Building on empirically-based estimates of a cumulative opportunity approach, we calculate the levels of accessibility at the traffic analysis zone level, evaluate how accessibility varies across age cohorts, and present the distribution of accessibility across zones. To this end, we draw on the 2015 Nanjing Travel Survey and the city’s GIS database. Instead of assuming a fixed threshold, this paper applies a spatial expansion model to allow for person- and location-specific walking distances to measure accessibility. The spatial disparities in access to recreational amenities are evaluated using the notion of vertical equity for identifying areas that are better-off or worse-off. Our results show pronounced distributional effects of current land-use and transportation policies for different age cohorts. In particular, elderly people experience lower accessibility to chess/card rooms and urban parks than their younger counterparts. The empirical evidence in this research can inform planning and policy interventions and feed current scientific debates on the role of accessibility in addressing social inclusion for an age-friendly society

Measuring polycentric urban development : the importance of accurately determining the ‘balance’ between ‘centers’

In recent years, much research has been devoted to developing appropriate analytical frameworks to capture polycentric urban development (PUD). In a recent contribution to this journal, Bartosiewicz and Marcińczak (2020) present what is arguably the most comprehensive, comparative review to date of the degree to which different analytical frameworks produce consistent results. The purpose of this research note is to show why we believe parts of Bartosiewicz and Marcińczak's (2020) findings need nuance and qualification. Our starting point is that a useful comparison between different studies and measurement frameworks needs to consider the relevance of consistency in several key dimensions, two of which are particularly pertinent here: (1) the careful specification of what constitutes a ‘center’ in a polycentric urban system, and (2) the identification of the ‘balance’ between centers as a measure of the degree of polycentricity. Two brief empirical analyses of the degree of morphological polycentricity in Polish NUTS-3 areas and the Chinese city-regions along the ‘Yangtze Economic Belt’ are included. Finally, suggestions are provided to facilitate future comparative analyses of PUD