International Laboratory of Urban Form

The relation between pedestrian flows, the structure of the city and the street network is of central interest in urban research. However, studies of this have traditionally been based on small data sets and simplistic statistical methods. Because of a recent large‐scale cross‐country pedestrian survey, there is now enough data available to study this in greater detail than before, using modern statistical methods. We propose a functional ANOVA model to explain how the pedestrian flow for a street varies over the day based on its density type, describing the nearby buildings, and street type, describing its role in the city’s overall street network. The model is formulated and estimated in a Bayesian framework using hour‐by‐hour pedestrian counts from the three European cities, Amsterdam, London and Stockholm. To assess the predictive power of the model, which could be of interest when building new neighbourhoods, it is compared with four common methods from machine learning, including neural networks and random forests. The results indicate that this model works well but that there is room for improvement in capturing the variability in the data, especially between cities.

PST is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. The GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. It combines the space syntax description of the urban environment with conventional descriptions of attraction into the combined accessibility analysis tool PST. It is currently available as a plugin for the MapInfo Professional GIS software and QGIS, an open source GIS software. PST is developed by KTH School of Architecture, Chalmers School of Architecture (SMoG) and Spacescape AB. Alexander Ståhle, Lars Marcus, Daniel Koch, Martin Fitger, Ann Legeby, Gianna Stavroulaki, Meta Berghauser Pont, Anders Karlström, Pablo Miranda Carranza, Tobias Nordström. The software was first introduced in a paper by Ståhle, A., Marcus, L. and Karlström, A., (2005), ”Place Syntax: Geographic accessibility with axial lines in GIS”, published in the proceedings of the 5th Space Syntax Symposium held in Delft. PST is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. The application is available via: https://github.com/SMoG-Chalmers/PST/releases/tag/v3.1.4 Download: pstqgis_3.1.4_2020-02-07.zip Documentation, data and tutorials are available via KTH and Chalmers: https://www.smog.chalmers.se/pst https://www.arch.kth.se/forskning/urban-design/software The code is released under GNU GENERAL PUBLIC LICENSE and is available at https://github.com/SMoG-Chalmers/PST

A better understanding of the relationship between the built environment and urban processes is central in guiding urban processes in more sustainable trajectories. Of particular importance to this endeavour is the idea of urban types. However, on closer scrutiny, while such types may capture the symbolic dimension of urban form, they frequently do not capture its performance or functional dimension. This prohibits precise policy formulation on the topic. This paper first presents a methodology for generating urban types relevant to urban practice (using analytical and statistical methods) and, second, an empirical test of the differences in performance concerning their influence on the presence of people in public space (an essential driver of many other urban processes). For this reason, a large (and to our knowledge unique) pedestrian survey of three European metropolitan areas was conducted and used to test the performance of the urban types developed. The results prove that the methodology for developing the types is robust, as it picks up generally recognised spatial patterns in all three cities. Further, the types were able to explain the intensity of pedestrian flow, its spatial distribution and fluctuations of intensity in space and time. These are vital steps forward and provide more useable typologies in urban planning and design practice.

Typologies have always played an important role in urban planning and design practice and formal studies have been central to the field of urban morphology. These studies have predominantly been of a historical-qualitative nature and do not support quantitative comparisons between urban areas and between different cities, nor offer the precise and comprehensive descriptions needed by those engaged in urban planning and design practice. To describe contemporary urban forms, which are more diffuse and often elude previous historic typologies, systematic quantita-tive methods can be useful but, until recently, these have played a limited role in typo-morphological studies. This paper contributes to recent developments in this field by integrating multi-variable geometric descriptions with inter-scalar relational descriptions of urban form. It presents typologies for three key elements of urban form (streets, plots and buildings) in five European cities, produced using statistical clustering methods. In a first instance, the resulting typologies contribute to a better understanding of the characteristics of streets, plots and buildings. In particular, the results offer insight into patterns between the types (i.e. which types are found in combination and which not) and provide a new large scale comparative analysis across five European cities. To conclude, a link between quantitative analysis and theory is established, by testing two well-known theoretical propositions in urban morphology: the con-cept of the burgage cycle and the theory of natural movement.

This work follows a long line of studies and empirical investigations in Space Syntax research, that, in general, try to conceptualise, describe and quantify the relation between physical space and human agency. How many people share public space is known to affect many socioeconomic processes in cities, such as segregation, vitality and local commercial markets. Observing and measuring pedestrian movement through surveys, as well as statistically analysing it have been at the core of diverse investigations not least in the field of Space Syntax, not only a means to validate and measure the dependence of pedestrian movement on spatial configuration, but also as a means to forecast and predict pedestrian flows. However, these studies do not necessarily provide us with comparable, let alone generalisable findings that can lead to generalisable propositions. They remain in most cases specific investigations of particular cities, neighbourhoods or types of areas (e.g. city centres). Another issue, as will be elaborated in this paper, is that the typical statistical methods used, such as multivariate regression models, are not always the optimal or even suitable for modelling pedestrian movement, typically measured in pedestrian counts. This paper aims therefore, to directly address three methodological challenges: first, construction of comparable GIS-models; second, gathering large scale pedestrian data; third, applying advanced statistical modelling suitable for pedestrian data. The ultimate goal is to estimate the impact of spatial form on urban life in a way that is methodologically sound and can provide robust results that can be generalisable, and allows us to speak of the relation between spatial form and pedestrian movement in a way that is not specific to a certain area, or types of areas or streets, or even to a specific city. The results show, first, high and consistent correlations between spatial form and pedestrian movement in a study of unprecedented size that comprises three cities, including a large range of neighbourhoods of varying morphological types, from villa areas to urban cores, and offer convincing proof that the tested morphological variables have a strong impact on the spatial distribution of pedestrian flows in cities. Second, the study shows that the model with all explanatory variables has the highest explanatory power and the best model fit where Angular integration and Accessible FSI are the explanatory variables with the largest effect on pedestrian movement, but others are significantly contributing to the predictive power of the model. Third, the study contributes to the advancement of the statistical modelling that is suitable for the specificities of the data used, proposing the use of a negative Binomial model instead of regression models, most common in the field.

Typologies have always played an important role in urban planning and design practice and formal studies have been central to the field of urban morphology. These studies have predominantly been of a historical-qualitative nature and do not support quantitative comparisons between urban areas and between different cities, nor offer the precise and comprehensive descriptions needed by those engaged in urban planning and design practice. To describe contemporary urban forms, which are more diffuse and often elude previous historic typologies, systematic quantitative methods can be useful but, until recently, these have played a limited role in typo-morphological studies. This paper contributes to recent developments in this field by integrating multi-variable geometric descriptions with inter-scalar relational descriptions of urban form. It presents typologies for three key elements of urban form (streets, plots and buildings) in five European cities, produced using statistical clustering methods. In a first instance, the resulting typologies contribute to a better understanding of the characteristics of streets, plots and buildings. But especially, the results offer insight into patterns between the types (i.e. which types are found in combination and which not) and provide a new large scale comparative analysis across five European cities. To conclude, we establish a link between quantitative analysis and theory, by testing two well-known theoretical propositions in urban morphology: the concept of the burgage cycle and the theory of natural movement.

A better understanding of the relationship between the built environment and urban processes is central in guiding urban processes in more sustainable trajectories. Of particular importance to this endeavour is the idea of urban types. However, on closer scrutiny, while such types may capture the symbolic dimension of urban form, they frequently do not capture its performance or functional dimension. This prohibits precise policy formulation on the topic. This paper first presents a methodology for generating urban types relevant to urban practice (using analytical and statistical methods) and, second, an empirical test of the differences in performance concerning their influence on the presence of people in public space (an essential driver of many other urban processes). For this reason, a large (and to our knowledge unique) pedestrian survey of three European metropolitan areas was conducted and used to test the performance of the urban types developed. The results prove that the methodology for developing the types is robust, as it picks up generally recognised spatial patterns in all three cities. Further, the types were able to explain the intensity of pedestrian flow, its spatial distribution and fluctuations of intensity in space and time. These are vital steps forward and provide more useable typologies in urban planning and design practice.

We present the methodology and results of an international observational study on pedestrian movement, using innovative high-end technology of tracking anonymised Wi-Fi signals from mobile phones. The pedestrian survey was conducted during three weeks in October 2017 in 60 neighbourhoods across three cities in Europe - London, Amsterdam, Stockholm. The survey was led by Chalmers University of Technology in cooperation with Bumbee Labs consultancy firm. More than 300 streets of different network centrality profiles were monitored, ranging from small alleys to high streets, in neighbourhoods which differed in density type, from suburban villa areas of low density to central high-density areas with primarily closed building blocks. The aim is to quantify the separate and combined effects of spatial form, particularly built density and street centrality, on pedestrian movement. The collected data record how many people passed each street per hour, but also their average speed and exact paths through the area; revealing both flow patterns and intensities, and the microstructure of individual paths. We first, present the methodology and technology of collecting and processing anonymised pedestrian data through mobile phone Wi-Fi tracking and the results of the study. Then, results are tested against spatial variables and types to discuss how movement is influenced by street centrality, density and other attractors. Finally, we discuss the possible utilisations of pedestrian data in urban analysis and design, not least in a time when big data become increasingly accessible and when the boost of pedestrian mobility in cities is a central planning objective.

As cities are growing the need for complementary sub centres increases, both in order to distribute amenities and to make resources more accessible for citizens, as well as to relieve the pressure on the city core. Such planning strategy, a kind of decentralized concentration, has been seen as a mean for holding back urban sprawl in Stockholm. Lately, urban centres are also argued to contribute to the development of more equal living conditions making opportunities, service, and urban life accessible also in more peripheral urban locations. The values of 'suburban urbanities' has also been highlighted in a way that reach far beyond the commercial activities (Vaughan 2015). The Regional planning authority in Stockholm as well as the City of Stockholm identifies a number of regional subcentres and 'urban boulevards' that should connect the city since and make it less fragmented. The social incentive for this strategy is prominent in both plans. However, these subcentres are dependent on urban centrality which needs to be taken into consideration. The strength, or the success, of a subcentre is partly influenced by urban design interventions and is argued to be related to 1) the configurative properties (distribution of space) and 2) land use parameters and density (distribution in and through space) (Koch 2016; Hillier 1999; Vaughan 2010). In order to increase the understanding for what urban design interventions that may be efficient, this paper will draw from the concepts developed by Stan Allen (1999) of point, line and field and John McMorrough (2001). The combination of the configurative perspective and the point-line-field perspective is argued to contribute with knowledge of how urban form generates and supports the emergence of urban centrality and the development of subcentres with implications not only for consumption and mobility, but also for social outcomes such as urban life and equal living conditions. The empirical application aims to illustrate how configurative analysis complement the point-line-field theory in describing the character of the centres and the findings are argued to contribute to the identification of more precise and efficient urban design interventions of how to develop the centres.

It has been argued that different urban configurations-planned vs. organic, treelike vs. grid like-perform differently when it comes to the intensity and distribution of pedestrian flows, built density and land uses. However, definitions of urban configurations are often rather abstract, ill-defined and at worse end in fixed stereotypes hiding underlying spatial complexity. Recent publications define morphological typologies based on quantitative variables (e.g. Barthelemy, 2015; Serra, 2013a; Gil et al., 2012; Berghauser Pont and Haupt, 2010) and solve some of these shortcomings. These approaches contribute to the discussion of types in two ways: firstly, they allow for the definition of types based on multiple variables in a precise and repeattable manner, enabling the study of large samples and the comparison between both cities and regions; secondly, they frame design choices in terms of types without being fixed and so open up for design explorations where the relation between the variables can be challenged to propose new types. This paper explores the typologies defined by Serra (2013a) and Berghauser Pont and Haupt (2010) further, as these target two of the most important morphological entities of urban form, namely the street network and the building structure. The purpose is to gain a better understanding of how types are composed and distributed within and across different cities. The method is based on GIS and statistical modeling of four cities to allow for a comparative analysis of four cities: Amsterdam, London, Stockholm and Gothenburg. For the street network, we process the Road-Centre-line maps to obtain a clean network model, then run segment angular analysis to calculate the space syntax measures of betweenness at different metric radii, defining the " centrality palimpsest " (Serra, 2013a). For the building structure, we process elevation data to obtain building height, then run accessible density analysis for all building density metrics (FSI, GSI, OSR, L) using the Place Syntax Tool (Berghauser Pont and Marcus, 2014). The street and building types are defined using cluster analysis (unsupervised classification), following a similar approach to Serra (2013a). The result is a typology of street (´paths´) and building types (´places´), with different profiles of centrality and density across scales. The spatial distribution and frequency of these types across the four cities gives an objective summary of their spatial structure, identifying common as well as unique traits.

The central variables in any urban model are distance and attraction (Wilson 2000). Space syntax research has contributed to the development of new geometric descriptions and measures of distance that have proven successful when it comes to capturing pedestrian movement. However, the description and measurement of attractions has not been central to the field. An important exception is the development of Place Syntax analysis, which concerns new methodologies and software that open for analysis not only of different kinds of accessibilities in the street network in itself, but also analysis of the accessibility within the network to different forms of attractions, for instance, residences or retail (Ståhle et al 2005). Place Syntax analysis is a generic form of analysis, why we may choose to analyse the accessibility to particular socioeconomic attractions, but we may also conceive of a model of 'pure' spatial form-a kind of architectural model of the city. For instance, Place Syntax analysis has been applied in different kinds of density analysis, transforming density measures from area-based measures to location-based measures (Ståhle et al 2005). In this paper, we extend such spatial attraction to not only include the variable of density but also diversity and present results from an extensive empirical study of the city of Stockholm, paving the way towards a more complete architectural model of the city including both the analysis of distance and attractions.

Typologies play a role in urban studies since a long time, but definitions are often rather abstract, ill-defined and at worst end in fixed stereotypes hiding underlying spatial complexity. Traditional typologies are focussing on separate elements, which allow for understanding crucial differences of one spatial feature in greater detail, but lack the capacity to capture the interrelation between elements. Further, they often focus on one scale level and therefore lack to acknowledge for interscalarity. Recent publications define morphological typologies based on quantitative variables, building on the seminal book´Urbanbook´Urban Space and Structures´byStructures´by Martin and March, published in 1972, but using more advanced spatial analysis and statistics. These approaches contribute to the discussion of types in two ways: firstly, they define types in a precise and repeatable manner allowing for city-scale comparisons; secondly, they acknowledge cross-scale dynamics important for e.g. living qualities and economic processes where not only the local conditions are important, but also the qualities in proximity. This paper focuses on the comparison of building types in three Swedish cities, using the multi-variable and multi-scalar density definition. A statistical clustering method is used to classify cases according to their measured similarity across the scales. The results show that working with types is a fruitful way to reveal the individual identity of these types, compare cities and highlight some differences in the way the three cities are structured.