Shawlan
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Network Analysis of Streets
Analysis Stage prepared by, Berkay Gebitekin, Emma Poulton, Jakub Fraczek & Shinjini Basuzz Urban Design Studies Unit University of Strathclyde Glasgow
Booklet No.5
Introduc on For these 5 weeks, Group 5 have worked on the “Network Analysis of Streets� for Shawlands (Kilmarnock Road) in the South and Maryhill (Maryhill Road) to the North of Glasgow. Detailed study maps of the street networks for both the regions were generated by the help of computer so ware, Mompey and QGIS. These maps show the Betweenness, Closeness and Straightness Centrality of the two areas. The study of centrality has helped us understand how a city network func ons and to iden fy specific areas needing regenera on and redevelopment. With the help of this analysis, we aim to propose an altered scenario for each street that carefully shapes the growth of Greater Glasgow.
Authors Berkay Gebitekin
MSc in Urban Design, University of Strathclyde
Emma Poulton
Master of Architecture, University of Strathclyde
Jakub Fraczek
Master of Architecture, University of Strathclyde
Shinjini Basu
Master of Architecture, University of Strathclyde
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Network Analysis of Streets
Contents 01
Introduc on
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Objec ves
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Methodology
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Technical Notes
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Network
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Centrality
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Modelling the Exis ng High Street Exis ng Layout
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Betweenness
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Closeness
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Straightness
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Depriva on
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03
Scenarios Overviews
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Scenario 1: Link
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Scenario 2: Join
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Scenario 3: Connect
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Conclusion Conclusion
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Bibliography
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01
Introduc on
This chapter will introduce city networks, centrality, and the so ware Momepy. 1.1 Objec ves 1.2 Methodology 1.3 Network 1.4 Centrality
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1.1 Objec ves
1.Using the density of centrality of the study area rela ve to the surrounding areas in the system to analyse the exis ng network poten al to sustain an ac ve and varied local life. 2.To develop alterna ve scenarios with the aim of understanding the impact of proposed changes to the network on the study area and its surroundings.
1.2 Methodology A er being introduced to the concept of mul ple centrality analysis (MCA) by our tutors, the first step was to understand the underlying ideas of the analysis by researching the papers wri en on the said subject. Impor ng the Greater Glasgow areas network map from h ps://digimap.edina.ac.uk, we performed 6 MCA analyses using the so ware “momepy� which are as follows; - Global / Local Betweenness - Global / Local Closeness - Global / Local Straightness The tests are performed by the so ware Mompy on the basis of edges and nodes of the network. The results are then assigned to each node and averaged onto edges from the two end nodes that define them. The resul ng map was then loaded into qGIS and given a color legend to be er visualise as; - Red = High - Orange = Medium/High - Yellow = Medium - Green = Medium/Low - Blue = Low From these results we determined mul ple areas for interven on and tested a variety of scenarios by making changes to the exis ng network and re-tes ng the modified maps. The results that showed the biggest improvement and impact were chosen to be presented as alterna ve scenarios for the network of the study area and its surroundings.
1.3 Technical Notes The Glasgow Area tests were performed with a map radius of 12km and were then clipped to a 10km radius to alleviate the unwanted edge eect. The study area tests were performed with a map radius of 5km and were clipped down to 4km for the same reason. The analysis radius parameter used in the local betweenness and straightness variants of the test were 1000 steps and in the closeness variant it was 400 steps.
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Booklet No.5
1.3 Networks The city connec vity can be easily analysed when presented as a network, which deals with the rela onship between the “nodes” and the “links/edges”. The nodes represent the street intersec ons and links represent the streets. The network of streets show how well or poorly a city is connected . An efficient network helps in shaping a well accessed city. This efficiency is determined by the centrality of the space.Centrality is associated with the movement of people in a certain area and it is determined by its three indices: Betweenness, Closeness and Straightness. (Porta, S., Cruci , P., & Latora, V. 2008)
1.4 Centrality Betweenness Centrality: This is measured by how likely a par cular space in a city is probable to be passed through while travelling between the start point and the des na on (Porta, S., Strano, E., Iacoviello, V., et al. 2009).
Closeness Centrality: This represents the shortest or the actual distance between two nodes. Closeness may be explained as proximity as well as how accessible a place is. The closer a place is to the other, the more accessible it is ( Porta, S., Latora, V., & Strano, E. 2010).
Straightness Centrality: This is derived from the idea that less deriva on of the shortest path between to nodes increases the efficiency of their communica on. In other words, it expains that, the straighter the path easier it gets to find places (Porta, S., Latora, V., Wang, F., et al. 2011).
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Global (Authors’ own, 2019)
Local (Authors’ own, 2019)
“Global” and “Local” are important terms in the street network analysis (Porta, S., Latora, V., Wang, F., et al. 2011). In the global scale, the mompey so ware considers every node within the system, which means each node is assessed with every other node with the en re map. For the local scale, a certain radius is fed to the so ware so that it works on assessing each and every node present with the radius. For example, in a 400 mm radius, every node in that par cular radius is assessed with every other by the system. Any distance can be set for the radius. Both these Global and Local maps represent closeness centrality.
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02
Exis ng Road Analysis
This chapter will introduce Kilmarnock Road and it’s exis ng centrality 2.1 Exis ng Layout 2.2 Betweenness 2.3 Closeness 2.4 Straightness 2.5 Depriva on
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2.1 Exis ng Layout
(Digimap,2019)
This map shows Kilmarnock Road as exis ng in Shawlands. The study area stretches from Queens park to the train tracks and is indicated above with a black line. The pink oval shows a 400 meter radius around the study area. The high street is lined with tenement buildings hos ng shops and restaurants on the ground floor and flats above. There is also a shopping centre on the street housing more shops, a gym, banks, and other ameni es. Within the 400 meter radius more residen al tenements can be found along with two churches, two schools, medical and dental prac ces, a train sta on, and a football club. The street is well connected to it’s neighbourhood and has a vibrant community.
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2.2 Betweenness
Global (Authors’ own, 2019) The global scale betweenness analysis results show that while there are many inner and dead-end streets in the area, there is also an abundance of main travel paths and roads shown in red. It can also be noted that the network of the area consists of superblock style large development areas that are surrounded by these main circula on paths shown in red.
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Local (Authors’ own, 2019)
The local betweenness analysis show that while the eastern side of the Kilmarnock road is mostly well connected, the eastern side is lacking in connec veness both with the main circula on roads and within itself.
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2.3 Closeness
Global (Authors’ own, 2019) The global closeness analysis demonstrates that the main city and human ac vity lies towards the northeastern direc on of the study area.
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Local (Authors’ own, 2019) The local closeness analysis highlights certain areas to be well connected within themselves but this is not consistent throughout the analyzed area and within the study area there are long stretches of the Kilmarnock road that are lacking in connec ons to the surrounding inner roads.
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2.4 Straightness
Global (Authors’ own, 2019) The analysis shows that while the main roads have rela vely high straightness values, the surrounding road network includes a substan al number of nodes that are on the lower end of the scale.
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Local (Authors’ own, 2019) The local straightness analysis demonstrates the role topography and closed o residen al areas play in determining straightness values as the grid areas are shown as high straightness while the winding roads of the areas with bigger eleva on dierences are shown as low straightness.
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2.5 Depriva on
Map showing depriva on (Authors’ own, 2019) Depriva on is measured using four dimensions to classify housing in the UK: educa on, health and disability, employment, and household overcrowding (Nomisweb,2019). A household may be deprived in non or one to four of these dimensions in any combina on. The map above uses these dimensions to asses the depriva on in areas around Shawlands, with dark blue represen ng areas with the least number of deprived households, and red represen ng areas with the most number of deprived households (Scotland Datashine, 2019). There is a correla on between depriva on and centrality. For example, the area towards to lower le corner of this map shows high levels of household depriva on. This same area also showed low levels of centrality in the analysis maps in the previous chapter. The same can also be said for the area in the upper right corner. While more factors would need to be assessed to determine how much of a connec on lies between household depriva on and centrality, this map helped to asses areas that need interven on and could be helped with a be er connected network. It is important to note that other factors do affect the correla on between depriva on and centrality. Contrary to the observa on above, there is a dark blue area an area in the lower middle of this map that shows low levels of depriva on but also shows low levels of centrality in the previous chapter. This is because this area is purposefully disconnected from the surroundings as a form of “gated” community with more developed tenement apartments.
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Scenarios
This chapter will analysis alterna ve scenarios aiming to improve centrality 3.1 Overview 3.2 Scenario 1: Link 3.3 Scenario 2: Join 3.4 Scenario 3: Connect
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3.1 Overview Link: Kilmarnock Road and Pollokshaws Road are main streets of the Shawlands area, however there are no straight links between them. Perpendicular links in street network have been introduced in order to increase permeability of the nearest neighbourhood. This was achieved by minor changes of connec on exis ng road to exis ng node or extending exis ng segment.
(Authors’ own, 2019)
Join: High quality housing area to the east of Kilmarnock Road has scarce links to the main road, even though secondary streets come right up to it. Barrier on such intersec on was removed to allow through traffic, joining the housing area with the high street of our analysis.
(Authors’ own, 2019)
Connect: Marked area in corner of Pollokshaws and Nether Auldhouse Streets is disconnected from the rest of Shawlands by rivers and has only couple of entry points from main roads. Addi onal connec ons were introduced in try to improve general connec vity of the area.
(Authors’ own, 2019)
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3.2 Scenario 1: Link Betweenness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Betweenness - lobal: Althou h the link between Kilmarnock and Pollokshaws Roads near the point of their intersec on did not brin any chan es, connec ons created with streets further to the south and west have improved betweenness by much.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Betweenness - local: On local scale, introduced changes had similar effect as on global scale, although the perpendicular link near Pollokshaws and Kilmarnock Roads junc on did slightly improve betweenness of street south-east of Kilmarnock Road.
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Closeness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Closeness - lobal: Global closeness centre was shi ed sli htly to the west in the alterna ve scenario.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Closeness - local: Overall upgrade in local closeness centrality of not only secondary streets network but also of sec ons of Pollokshaws Road was achieved in this scenario.
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Straightness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Strai htness - lobal:Increased lobal strai htness of several streets can be observed in alterna ve scenario in comparison with exis n case. Possibly more links could be added between the nei hbourhood north from Pollokshaws Street and surroundin mian streets to increase its centrality
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Straightness - local: In local scale the improvement is even be er no ceable, with all three areas neighbourhoods affected, to the north of Pollokshaws Road, south-east of Kilmarnock Road, and between those two main streets.
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3.3 Scenario 2: join Betweenness
Global: Exis ng
Global: Alterna ve
Betweenness - lobal: Previously separated roads with lowest betweenness scores moved to the hi hest scores in the alterna ve scenario.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Betweenness - local: On a local scale, introduced link took high betweenness from one street in original scenario and distributed it among other streets in the alterna ve case.
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Closeness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Closeness - lobal: Proposed alterna ve made all nearby streets included in the hi hest centrality zone.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Closeness - local: Local closeness was slightly improved by connec ng least central streets to Kilmarnock Road. It also affected sec on of the high street north from the junc on, improving its score.
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Straightness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Strai htness - lobal: The hi h-quality housin nei hbourhood east of Kilmarnock Road have si nificantly improved strai htness centrality thanks to proposed chan e.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Straightness - local: Local straightness scores of nearby streets have improved even be er than global, with both sides of Kilmarnock Road and that road itself showing visible change in centrality scores.
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3.4 Scenario 3: Connect Betweenness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Betweenness - lobal: Proposed connec ons show moderate move of betweenness centrality from southern ed e of the area. Possibly more connec ons throu h to Pollokshaws Road would be beneficial.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve(Authors’ own, 2019)
Betweenness - local: In local betweenness, alterna ve scenario shows be er gains than on global scale, with the whole area having higher centrality score.
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Closeness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Closeness - lobal: As in previous scenarios, lobal closeness centre moved sli htly to the west, affec n sli htly selected area.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Closeness - local: Alterna ve scenario connec ons allowed high centrality zone on the north-eastern end of discussed area to be dissolved towards south-west.
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Straightness
Global: Exis ng (Authors’ own, 2019)
Global: Alterna ve (Authors’ own, 2019)
Strai htness - lobal: Global strai htness score increased visibly a er implemen n proposed chan es.
Local: Exis ng (Authors’ own, 2019)
Local: Alterna ve (Authors’ own, 2019)
Straightness - local: This centrality assessment shows poten ally highest varia on, with local straightness improved at Pollokshaws Road at the north edge of changed area, just as the street marking its souther edge, however reducing centrality on the south-eastern edge. In general, introduced connec ons show good straightness values.
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Conclusion
It is easy to see where the altera ons made in the previous chapter have improved network centrality around Kilmarnock Road in Shawlands. The changes to improve the link between Kilmarnock Road and Pollockshaws Road oer easier routes for people to follow, which is especially important in the busy area around Shawlands Cross. The decision to join the high quality housing area to the east back to Kilmarnock Road breaks down an exis ng social barrier to integrate people and encourage a more diverse range of people to use the high street. By connec ng the area in the corner of Pollockshaws Road and Nether Auldhouse Streets with the surroundings, be er access is given between peoples homes and the shops in that area which improves convenience of life. While the altera ons made in this study have certainly improved centrality of Kilmarnock Road and the surroundings, there may be other small changes that could help as well. A con nua on of this study could see further scenario analysis focusing on small road changes as seen so far. This would be recommended over drama c altera ons as the network around the study area is already well developed and any dras c changes could disrupt the exis ng community while not oering a large advantage to centrality.
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Network Analysis of Streets
References Digimap. (2019). Retrieved November 16, 2019, from h ps://digimap.edina.ac.uk/? clid=IwAR2ybNIrH9uQI9aP_ rIxQQF1H5CH2JGrZ7gBdnCKEyl70BJpUFYrwfzwmZo Nomisweb. (2019). h ps://www.nomisweb.co.uk/census/2011 Porta, S., Cruci , P., & Latora, V. (2008). Mul ple centrality assessment in Parma: a network analysis of paths and open spaces. URBAN DESIGN Interna onal, 13(1), 41–50. h p://doi.org/10.1057/udi.2008.1 Porta, S., Latora, V., & Strano, E. (2010). Networks in Urban Design. Six Years of Research in Mul ple Centrality Assessment. Network Science, 107–129. h p://doi. org/10.1007/978-1-84996-396-1_6 Porta, S., Latora, V., Wang, F., et al. (2011). Street Centrality and the Loca on of Economic Ac vi es in Barcelona. Urban Studies, 49(7), 1471–1488. h p://doi. org/10.1177/0042098011422570 Porta, S., Strano, E., Iacoviello, V., et al. (2009). Street Centrality and Densi es of Retail and Services in Bologna, Italy. Environment and Planning B: Planning and Design, 36(3), 450–465. h p://doi.org/10.1068/b34098 Scotland Datashine. (2019). h ps://scotland.datashine.org.uk/#table =QS108SC&col=QS108SC0007&ramp=RdYlBu&layers=BTTT&zoom=12&lon=4.2407&lat=55.8559 All Mompey Maps have been generated by us.
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