Drumchapel | Network analysis of streets | Analysis

Booklet no.5

Network analysis of streets October 2017

Drumchapel

Stage: Analysis Group memebers: Aleksandra Patarova Hristo Indzhov Veselina Chavdarova Zhenghao Gan

Department of Architecture University of Strathclyde Glasgow strath.ac.uk/engineering/architecture/ PgDip/MArch Advanced Architectural Design (AAD) MArch Architectural Design International (MADi) PgDip/MSc Urban Design

CONTENTS

I. Introduction Drumchapel Objectives of Study What is Centrality?

Kernel Density Estimation Methodology Vehicular Network Pedestrian Network

II. Modeling the Existing City Glasgow Metropolitan Area 1.

2.

3.

4.

5.

Betweenness Centrality Global Closeness Centrality Local Closeness Centrality Straightness Centrality Kernel Density Estimation

Drumchapel 1.

2.

3.

4.

General Overview Betweenness Centrality Closeness Centrality Straightness Centrality

4 4 4 5 5 6 7 7

8 8 10 12 14 16 18

20 22 26 30 34

III. Modeling Scenarios

38

Scenario 1 Scenario 2 Scenario 3

40 42 44

IV. Conclusion V. Bibliography

46 48

Booklet no.5: Network analysis of streets

I. Introduction Drumchapel

Objectives of Study

Drumchapel is an area of Glasgow developed as part of the overspill policy of Glasgow City Council in the 1950s. Like the rest of the “Big Four” post-war social housing schemes within Glasgow (Easterhouse, Castlemilk and Pollock) it sufers from a wide-range of issues, one of the main of which is its lack of connectivity – both externally within the wider Glasgow area and internally within the neighbourhood itself.

This report aims to address the relationship between street and pedestrian path layout and their centrality within Drumchapel and determine its future potential for further prosperity. Thus, the research has been conducted in two stages: analysis of the existing vehicular and pedestrian street network and “modelling” alternative scenarios for the network.

Overall, Drumchapel is not easy to navigate through as its varied topography, meandering streets and multiple gap sites render certain areas less accessible.

The key objectives of the irst stage of the report are to assess Drumchapel’s connectivity with wider Glasgow and Clydebank, and on a more local level – to identify which streets are more/ less central and which areas need improvement.

Good accessibility is linked to how central a place is and centrality is of crucial importance for creating vibrancy and desirability - central places represent urban “nodes” with intensive land use, high density of retail and service activities, as well as higher intrinsic value (Porta, Latora, 2009).

Fig. 1: Aerial view of Drumchapel

4

The scenarios forming the last part of the report aim to address Drumchapel’s connectivity issues and also put forward possible routes for future improvement by analysing the inluence of local alterations on the overall street system.

Drumchapel

What is Centrality?

Network NODE

K

LIN

LINK

In most basic terms a “central” place is “a place that is close to all others” (Porta, Romice 2017: 3). When it comes to a complex system such as the city, there is, however, more intricacy and complexity in the hierarchical comparison between individual places.

LINK NODE

NODE LIN

K

NODE

A system composed of “nodes” and “edges”/ “links” that is used to described the relationship between separate entities e.g. people or places.

The nodes of spatial networks (e.g. rail network) have well deined coordinates in space.

Fig. 2: Network Deinition

Betweenness Centrality In order to assess centrality, the city is viewed as an Urban Street Network, where streets form the “edges”, or the connecting parts of the network, and their intersections form “nodes” (Fig.2). Centrality represents the value assigned to each node through a mathematical computation of its distance to all other points.

The formula for this computation depends on the “index”, or the “deinition”, of centrality.

When analysing Urban Street Networks, three indices of centrality are used: Betweenness Centrality (Fig. 3), Closeness Centrality (Fig. 4) and Straightness Centrality (Fig. 5).

Furthermore, centrality can be calculated globally, i.e. with reference to all nodes within the system, or locally, i.e. with reference to nodes within a set boundary.

Once the centrality of a network has been calculated, the results can be extrapolated on a grid to show the Density of Centrality (Fig.6).

Space has a smoothing quality: the dynamics that happen in it are not limited to singular nodes, instead places that are located in near proximity have inluence on each other. A street with high centrality exerts an inluence on the centrality of adjacent spaces, which decreases with distance. Mapping the density of centrality emphasizes the prominence of intersections and allows us to predict the pattern for the intensity of use. The smooth representation of the distribution of centrality is also refered to as Kernel Density.

Measures the likelihood of a segment to act as the shortest path between other nodes. A node with high betweenness is reachable via many routes and is likely to generate more activity, while low betweenness means that routes have to be diverted.

Fig. 3: Betweenness Centrality

Closeness Centrality Measures the amount of connections a segment has along the shortest path. High closeness amounts to a large number of connections within a short distance and reveals the structural density of the urban layout.

Fig. 4: Closeness Centrality

Straightness Centrality Measures the accessibility of a node by comparing its actual distance to other nodes with the shortest linear path. High straightness translates into many direct routes and easier navigation between individual nodes (e.g. grid patterns).

Fig. 5: Straightness Centrality

Kernel Density Estimation Smoothens the transitions between centrality in space and represents the dynamic relationship between places.

Its analysis captures the importance of corners.

Fig. 6: Density of Centrality

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Booklet no.5: Network analysis of streets

Methodology The existing vehicular and pedestrian networks were generated in QGIS by updating an existing OS street network map of Scotland downloaded from digimap.edina.ac.uk with iled information recorded during site surveys (Fig. 7). When constructing the network, the central line of streets and paths was taken as reference.

Fig. 7: Field Data Record

The resulting maps were input into Multiple Centrality Assessment (MCA) software, provided by Prof. Sergio Porta. The MCA is a tool which measures centrality by calculating the centrality index for each node based on a mathematical formula. The results are then graphically represented through a colour ramp (gradient), where red indicates the highest levels of centrality and blue – the lowest levels.

Streets were re-assigned into 10 classes with an equal number of features (adopting a quantile method of data distribution), each class designated with a set colour (Fig. 10).

Thus, the graphical representation of individual links within the network is relative to the scope of the network, which explains why streets with higher centrality within the Drumchapel network might be less prominent on the Wider Glasgow street network. The Kernel Density Estimation was calculated by interpolation of the calculated graphs on a ixed grid and power inversely proportional to distance.

6

2 km 4 km

6 km 8 km 10 km

Fig. 8: Glasgow Metropolitan Area Scope of Survey

400m 800m 1200m 1600m

3200 m

In order to analyse both Drumchapel’s global centrality in relation to the wider context of Glasgow Metropolitan Area, and its local centrality relative to immediate surroundings, three sets of network maps were produced: street network map of Glasgow with a scope of 360 km2 (Fig. 8), a vehicular and nonvehicular traic network map of Drumchapel with a scope of 16 km2 (Fig. 9). It should be noted that the cropping might have resulted in deviations in the centrality values along the edges of the network.

5000 m Fig. 9: Drumchapel’s Local Area Scope of Survey

Fig. 10: Histogram of the closeness centrality data for Glasgow

Drumchapel

Vehicular Network The vehicular network consists of all streets traversed by cars, buses and other motor vehicles. It’s layout has an impact on the traic in the area and public transport links, which in their turn afect the accessibility to services, facilities and activities outside the neighbourhood. Even though some of the streets (Fig. 13) in Drumchapel are not currently in use of their full civic potential, they have also been taken into account, as they have the capacity to serve as links now and in the future.

Fig. 11: Cloan Avenue

Fig. 12: Garscadden Road toward Old Drumchapel

Fig. 13: Invercanny Drive

Pedestrian Network The pedestrian network consists of the streets and paths accessible to pedestrians and cyclers.

In Drumchapel, most of these are shortcuts between housing estates or parks paths. Thus, places that appear central on the pedestrian network in reality may not have the same intensity of use as central places on the street netwrok map. However, analysing centrality within the pedestrian network is useful for deducing the potential of existing pedestrian connections may be converted to streets.

Fig. 14: Pedestrian path nearby Cloan Avenue

Fig. 15: View from Glenkirk Drive towards Garscadden Burn

Fig. 16: Pedestrian Paths beside Carolside Drive

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II. Modeling the Existing City GLASGOW METROPOLITAN AREA

Area of Study

Drumchapel

2 km

m 4 km

6 km

k 8 km

City Centre

1 : 100 000

Existing Street Network of the Western part of Glasgow Metropolitan Area within a 9km radius

Booklet no.5: Network analysis of streets

1. Betweenness Centrality Road Network Drumchapel (see “Detail 1” on the right)

City Centre (see “Detail 2” on the right)

1 : 6 000km

10

Drumchapel

Detail 1: Drumchapel

In the scale of the wider urban area and in comparison with the centre of Glasgow, it is evident that Drumchapel’s street network is a lot less dense and therefore less connected.

In the case of the City Centre (see “Detail 2” above), the high centrality is driven particularly by the M8 to the west, High Street to the East and the streets in the centre connecting to the South bank. These streets are important intermediaries in the urban area and one must go through them in order to eiciently get to other places.

Detail 2: City Centre

1 : 3 000km

destination within the overall network, i.e. people do not go through Drumchapel in order to reach other places. Therefore, its potential as a setting for activities and interaction is inherently reduced.

A810 Drymen Rd Great Western Rd

Great Western Rd

Glasgow Rd

In the case of Drumchapel (see “Detail 1” above), we see that it does not hold a central position as an intermediary. The A810, Great Wester Road and Drymen Road (passing through Bearsden) go around Drumchapel and consequently it is not an important linking CONCLUSIONS AND AIMS Great Western Road and Caniesburn Road have high betweenness centrality, but both of them circumpass Drumchapel. Thus, the creation of a backone of streets with high betweenness centrality should be a priority for Drumchapel.

Primary Network 1 : 12 000km

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Booklet no.5: Network analysis of streets

2. Global Closeness Centrality Road Network Drumchapel (see “Detail 1” on the right)

City Centre (see “Detail 2” on the right)

1 : 6 000km

12

Drumchapel

Detail 1: Drumchapel

This study of Global Closeness aims to examine the relationship between Drumchapel (see “Detail 1” above) and Glasgow City Centre (see “Detail 2” above) in an aerial context that includes both. Hence, the geographic centre of the study is in the middle between the two.

Yet, it is evident that the areas close to the City Centre score a more central position globally.

That is the result of a better-connected street network in the centre compared to Drumchapel’s.

Detail 2: City Centre

12km Drumchapel 10km Braehead 8km

6km

4km

At the same time, there is a visible diference between peripheral zones which are equally removed from the City Centre (see diagram to the right). For example, Breahead and Hillington are each roughly the same distance away from Glasgow’s centre as Drumchapel, but they have a higher level of global centrality.

CONCLUSIONS AND AIMS Drumchapel is a peripheral area of Glasgow, so by deinition, it canot hold a central position in the overall metropolitan area. However, connections to Drumchapel can be improved in order to achive better connectivity to the centre.

1 : 3 000km

City Centre 2km

Hillington

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Booklet no.5: Network analysis of streets

3. Local Closeness Centrality Anniesland

Road Network

Great Western Rd

Drumchapel

West End (Partick, Dowanhill, Hillhead)

(see “Detail 1” on the right)

Clydesbank

City Centre

(see “Detail 3” on the right)

(see “Detail 2” on the right)

Scotstounhill (see “Detail 4” on the right) 1 : 6 000km

14

Drumchapel

Detail 1: Drumchapel

Detail 2: City Centre

1 : 3 000km

Glasgow city centre is a dense interconnected network and therefore is classiied as very central in this category. Additionally, Great Western Road spurs centrality in the west urban periphery, particularly around Partick, Dowanhill and Hillhead. After a spot of condensed centrality around the major intersection at Anniesland, levels of closeness begin to decrease further west. Within this wide area context, Scostounhill (see “Detail 4�) also shows high levels of centrality in this study of local closeness at 800m as a result of its dense local streets network.

Within the scope of the wide urban area, Drumchapel appears less central due to the fact that its local network of streets is interrupted and less dense. Although some streets might be geographically close, there are no connections between them, hence the low closeness centrality.

CONCLUSIONS AND AIMS As it is located in the urban periphery, it is unlikely that the global closeness of Drumchapel could be improved signiicantly.

However, densifying its internal street network would improve the local closeness and make it similar to that of the West End.

Detail 3: Clydesbank

Detail 4: Scotstounhill

1 : 3 000km

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Booklet no.5: Network analysis of streets

4. Straightness Centrality Road Network

Great Western Rd Bearsden Rd

Drumchapel (see “Detail 1” on the right)

A739 Clyde Tunnel

16

M8

City Centre (see “Detail 2” on the right)

Drumchapel

Detail 1: Drumchapel

Not only are the streets of the city centre straight, but they are also mutually intersecting thus making communication direct and eicient.

In this category and wide urban scale, the east side of Glasgow appears more central than the west. That is a result of the relatively straight east-west axes, which are nonetheless well connected to other local street networks, in Glasgow’s East End. Although the M8 itself is of high straightness centrality, it appears to be impeding the east- west permeability between the city centre and the West End. Thus, routes westward of the city centre are less direct and eicient because one must overcome this north-south barrier. Consequently, this abrupt decrease in straightness centrality continues further west.

Detail 2: City Centre

1 : 3 000km

Drumchapel, is Great Western Road. However, as it gets further away from the city centre, its path becomes winding and it looses its straightness centrality. Another route of medium centrality levels is the A739 coming from the south bank, crossing through the Clyde Tunnel and continuing past the intersection at Anniesland and up through Bearsden Road, without passing through Drumchapel.

Drumchapel’s twisting and turning street network renders it very ineicient in terms of direct accessibility between streets.

Consequently, it scores very low on the scale of straightness centrality.

Drymen Rd

The main artery connecting the city centre with the western urban periphery, inlcuding CONCLUSION & AIMS To improve Drumchapel’s straightness centrality, better connections should be sought both externally - by introducing direct links to Great Western Rd and Bearsden Rd/ Drymen Rd, and internally - by introducing straighter street connections.

Great Western Rd

A739

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Booklet no.5: Network analysis of streets

5. Kernel Density Estimation Drumchapel

Drumchapel

City Centre

KDE Global Closeness

KDE Closeness 800m

1 : 200 000

1 : 200 000

TECHNICAL NOTE Due to the method of data interpolation (power inversely proportional to distance; based on a radius of 9km), to smoothen the results large areas between streets are illed with a colour gradient. Most often, as visible on the KDE Closeness 800m and KDE Straightness diagrams), the end result is a yellow-green ill. This, however, does not mean that those areas have medium centrality, as altogether they are not part of the urban street network.

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City Centre

As it is logical to expect, the City Centre of Glasgow has the highest centrality, with its inluence subsiding with distance. In terms of global centrality within the Glasgow Metropolitan Area, Drumchapel has medium centrality as it inherently occupies the urban periphery.

In terms of local closeness, it has medium to low centrality and compared to other parts of wider Glasgow such as Paisley and Newton Mearns it lacks an area with high closeness that could best serve as its local centre.

Drumchapel

Drumchapel

Drumchapel

City Centre

City Centre

KDE Straightness

KDE Betweenness

1 : 200 000

1 : 200 000

The City Centre and East End of Glasgow have a well deined straightness centrality due to their grid pattern. The high number of bridges across the river within there also means that the area with high straightness centrality extends south of the river.

The KDE map demonstrates that straightness centrality disperses west of the City Centre with Drumchapel and Clydebank occupying an area with very low centrality and thus negatively inluencing the centrality of the West End as well.

The KDE Map for Glasgow’s Betweenness Centrality highlights the function of motorways and main arterial roads in terms of connecting Glasgow’s City Centre with the towns and districts that lie in its urban periphery. Thus, the highest density of centrality for this index is not at the City Centre, but at the intersections between the main transport roads.

As noted, above Drumchapel is located northeast of Great Western Road, whose coeicient of betweenness is not high enough to have a signiicant efect on Drumchapel’s overall centrality.

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II. Modeling the Existing City DRUMCHAPEL

Area of Study

400m

800m

1200m

1600m

1 : 20 000

Drumchapel: Existing Street and Pedestrian Path Network within a radius of 1.6km

Booklet no.5: Network analysis of streets

1. General Overview Topography & Urban Fabric Heigher Areas (see “Detail 1” on the right)

Lower Areas (Valley) (see “Detail 2” on the right)

1 : 20 000

22

Drumchapel

Detail 1: Higher Areas

Drumchapel has an extremely varied topography which has an inluence on how its street network has been laid out.

While its south-east side lays low, higher grounds line its northern edge, and there is a valley along the Garscadden Burn, which runs through the middle of Drumchapel. However, as shown above, while the hills in the north-west part of Drumchapel are relatively built-up (see “Detail 1”), the valley has been left undeveloped and currently acts as a public park (see “Detail 2”). Its steep slopes mean that currently there aren’t any roads passing perpendicularly across.

CONCLUSIONS AND AIMS Even though Drumchapel’s topography is challenging and should be taken into account when laying out future street network proposals, it should be treated so as to achieve best results in urban connectivity. The presence of so many gap sites presents an opportunity for repairing its patched-up urban fabric and re-building connections between places.

Detail 2: Lower Areas (Valley)

1 : 30 000

Consequently, for more than 1 km and it acts as a natural barrier between north and south Drumchapel. As a result of that, the area west of it is interconnected and has denser urban fabric, while the north is relatively isolated and undeveloped.

Topography 1 : 40 000

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Booklet no.5: Network analysis of streets

Transport & Connectivity First Glasgow Lines

ScotRail

CB2 Drumchapel Local Lines

Drumry

24

Drumchapel

W

Drumchapel

Drumry

Drumchapel

Railway Network

Bus Network Garscadden Burn

Public Transport: There is a direct ScotRail train service to Drumchapel from Glasgow City Centre, as well as from Dalmuir, Larkhall, Motherwell, Airdrie, Balloch. However, the train station is located at the south side and due to topographic conditions not conveniently accessible for people in the north side.

Additionally, there is a bus service provided

by First Glasgow lines to Govan, Scotstoun, Clydebank, Easterhouse, Hilington, Dumbarton (First UK Bus, 2017), as well as the City Centre and a CB2 local service (SPT, 2017). The density of bus stops ensures coverage of most areas.

Pedestrian Paths

Public Facilities and Nodes: Most of the facilities in Drumchapel are at its south-west area along Duntreath Ave and Drumry Rd. This uneven dispersal of services further reduces the opportunity to accommodate for daily needs without vehicular use.

Duntreath Ave

Garscadden Rd

Drumry Rd E

Drumchapel Rd

CONCLUSIONS AND AIMS An improvement in the street connections can create conditions for the development of better public space and even distribution of facilities, thus improving local quality of life and walkability levels.

Main Roads and Public Facilities

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Booklet no.5: Network analysis of streets

2. Betweenness Centrality Road Network

Linkwood Dr Study Area B

Drummore Rd Study Area A Kinfauns Dr

Kinfauns Dr

Antonine Rd

Drumry Rd Drumchapel Rd Duntreath Ave 1 : 20 000

26

Drumchapel

As noted before, Drumchapel is accessed through Great Western Road, which is one of the chief intermediaries within the Glasgow Metropolitan Area. Thus, the streets branching out of it (Duntreath Ave/ Kinfauns Dr, Antonine Rd, Garscadden Rd, etc.) also have high betweenness centrality. Together with Drumchapel Rd, which is the main artery connecting Drumchapel to Bearsden, they form the backbone of the district.

Kinfauns Dr Linkwood Dr Great Western Rd

Drumchapel Rd/ Caniesburn Rd

On the basis of the above, we can identify the main axes of Drumchapel: North-South: Duntreath Ave - Kinfaus Dr East-West: Drumry Rd - Garscadden Rd - Drumchapel Rd Drumry Rd - Linkwood Dr - Blackcraig Ave Kinfaus Dr Circumscription: Antonine Rd - Lochgoin Av - Ladyloan Ave Drummore Rd While the east-west axes work well, the fact that there is just one norht-south axis and it is located in the western part of the neighbourhood means that the north-east and south-east areas are disconnected despite being geographically close. Also, there is a lack of a neighbourhood core accessible form all sides.

Primary Network 1 : 40 000

Somewhat contradictory, the Kernel Density Estimation shows the south-east of Drumchapel as the area with the highest betweenness centrality. This is attributed to the inluence of Drumchapel Rd/ Canniesburn Rd; however, those are connections out of Drumchapel and thus do not have the potential to become an anchor for the neighbourhood.

CONCLUSIONS AND AIMS Despite Drumchapel’s good betweenness centrality on a local scale, a new vertical axis through the Garscadden valley could reinforce the connection between south and north and help establish a neighbourhood core.

Kernel Density 1 : 40 000

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Booklet no.5: Network analysis of streets

Pedestrian Network Garscadden Burn Valley Study Area B Kinfauns Dr Glenkirk Dr Study Area A

Drumchapel Rd Linkwood Dr 1 : 20 000

28

Betweenness Centrality

Drumchapel

Vehicular Network Study Area A

Including pedestrian paths in the betweenness centrality assessment has signiicant impact on the betweenness of certain streets.

1 : 30 000

Similarly, the pedestrian paths crossing Garscadden Burn valley immensely improve the connectivity between the north and the south of Drumchapel and increase the centrality of the streets they connect to. Most crucially, the two paths crossing the valley vertically have very high centrality, which continues when they join Glenkirk Dr all the way down to Drumchapel Rd. Thus, a route that follows either of those paths has the potential to become part of a new north-south axis through Drumchapel.

Betweenness Centrality

In the north of Drumchapel (Study Area A), the vehicular street pattern seems disjointed and uninished, with all the streets locked between Linkwood Dr and Kinfaus Dr (Airgold Dr, Ledmore Dr, etc.) having medium to low betweenness centrality. This changes dramatically when the pedestrian paths which intersect and interconnect them are included.

Pedestrian Network Study Area A

Vehicular Network Study Area B

Pedestrian Network Study Area B

1 : 30 000

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Booklet no.5: Network analysis of streets

3. Closeness Centrality

Ladyloan Ave

Road Network Local Closeness

Study Area B

Study Area A

Linkwood Dr

Fettercairn Ave

Kinfauns Dr

Glenkirk Dr Drumchapel Park 1 : 20 000

30

Drumchapel

The image on the left shows Drumchapel’s closeness centrality on a neighbourhood level (400m), while that on the right, shows the same centrality index on a larger scale of 800m.

Drumchapel Park Industrial Area

Linkwood Dr Kinfauns Dr

On a neighbourhood scale, only two areas have relatively high closeness centrality: the residential area north-west of Drumchapel Park, especially along Fettercairn Avenue; and to a lesser scale - the residential development locked between Linkwood and Kinfaus Dr. Both of those areas have been recently developed and have a denser street network and smaller plot sizes. Long streets with few intersections such as Ladyloan Ave in the north, Glenkirk Dr and the eastern portion of Kinfaus Dr have very low closeness centrality. As visible on the Kernel Density Estimation, this renders whole areas in the east of the neighbourhood isolated and hard to reach within a walking distance.

Drumchapel’s industrial area also has low closeness centrality; however, this is to be expected with the larger plot sizes required for industrial parks.

Closeness Centrality 800m 1 : 40 000

Drumchapel’s closeness centrality improves when assessed on a scale of 800m, with the whole area west of Kinfaus Drive having medium to high centrality due to higher number of street intersections there. However, there is little change in the centrality of Drumchapel’s north-east and south-east periphery, which demonstrates that the street pattern lacks structure and density.

CONCLUSIONS AND AIMS By leveraging the large amount of undeveloped land north of Linkwood Drive, there is potential for improving Drumchapel’s closeness centrality in the north by introducing a denser street network. It would be harder to introduce density in the west, which is more built-up, unless connections westward with Bearsden area sought.

Kernel Density 1 : 40 000

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Booklet no.5: Network analysis of streets

Pedestrian Network Ladyloan Ave Study Area B Kinfauns Dr Bearsden Study Area A

Invercanny Dr

Garscadden Burn Valley 1 : 20 000

32

Closeness Centrality

Drumchapel

Vehicular Network Study Area A

Due to its high density of intersections, the non-vehicular network has a much higher closeness centrality than the vehicular network - especially within the areas in the north and east that were identiied as having the lowest centrality according to the KDE.

1 : 30 000

not included in the analysis.

The changes in Study Area B are even more dramatic with the closeness centrality of the streets and paths there jumping from low to high. It should be noted that this does not mean that those paths are used a lot, nor is it going to be possible for their routes to be replicated.

However, widening and establishing vehicular traic along some of them, speciically those extending to Bearsden, will have a positive efect on Drumchapel’s centrality.

Closeness Centrality

The paths crossing the woods and connecting Invercanny Dr, Kinfauns Dr and Ladyloan Ave all have medium centrality and the centrality of the streets themselves also improves signiicantly compared to when the paths are

Pedestrian Network Study Area A

Vehicular Network Study Area B

Pedestrian Network Study Area B

1 : 30 000

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Booklet no.5: Network analysis of streets

4. Straightness Centrality Road Network

Garscadden Burn Valley Southdeen Av Study Area B Kinfauns Dr

Study Area A Achamore Rd

Kinfauns Dr

Bearsden

Belsyde Ave

1 : 20 000

34

Drumchapel

On a local scale, Drumchapel’s straightness centrality improves compared to its MCA results as part of the Glasgow Metropolitan Area.

Being Drumchapel’s north-south axis, Kinfaus Dr has very high straightness centrality in its western part before it makes a sharp turn on itself. In addition, streets west of it have good overall centrality, with enough intersections between themselves and Great Western Road.

The housing development in the north-west side of Drumchapel, beside Achamore Road also has high straightness centrality due to the grid pattern of its streets.

In contrast with that, in the east meandering streets with few intersections such as Southdeen Ave, Jedworth Ave, and Belsyde Ave (which makes a loop) have the lowest levels of straightness centrality. Located along the valley of Garscadden Burn, those streets have already been identiied as poorly integrated in the street network.

The Kernel Density Estimation below, supports the observation that in terms of straightness centrality Drumchapel is divided into “west of Kinfaus Drive” and “east of Kinfaus Drive” with respectively good and poorer centrality.

Bearsden also has low levels of straightness centrality, where it edges Drumchapel due to the large number of streets that end abruptly without connecting to Kinfaus Drive.

CONCLUSIONS AND AIMS Straightness centrality is strongest where streets form a grid pattern and have many mutual intersections, so it would be beneicial to introduce such a pattern within new developments.

Kernel Density 1 : 40 000

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Booklet no.5: Network analysis of streets

Pedestrian Network Garscadden Burn Valley Southdeen Av Kinfauns Dr

Study Area B

Study Area A

Drumchapel Park

Garscadden Rd / Drumchapel Rd 1 : 20 000

36

Straightness Centrality

Drumchapel

Vehicular Network Study Area A

Including pedestrian paths does not result in drastic diferences with the straightness centrality for the road network, like the ones observed during the comparison for the closeness centrality. Nonetheless, there is an overall improvement in the centrality index.

1 : 30 000

On the other hand, the pedestrian paths in Garscadden Burn valley have a signiicant efect on the straightness centrality of adjacent streets. The centrality of Southdeen Avenue and Souhdeen Drive is signiicantly improved by those additional connections from low to medium, while that of Garscadden Road and Drumchapel Road becomes slightly lower. Therefore, it can be expected that introducing vehicular traic along a route that crosses Garscadden Burn will have a positive impact on the straightness centrality of streets north of the valley.

Straightness Centrality

Despite the large number of pedestrian paths in Drumchapel Park and between the housing developments (between Kinfauns Drive and Ledmore Drive), the straightness centrality of eather of those streets doesn’t improve.

Pedestrian Network Study Area A

Vehicular Network Study Area B

Pedestrian Network Study Area B

1 : 30 000

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III. Modeling Scenarios

Drumchapel

As a result of the analytical study of the existing pedestrian and vehicular paths, it became evident that there is a clear lack of welldistributed centrality features in Drumchapel, which is especially evident in its geographic centre and just to the north of it. Taking these indings as a prompt, the following scenarios try to point in the direction of addressing and resolving the most prominent gaps in Drumchapel’s street network:

Scenario 1: Increasing Local Street Density

+

Scenario 2: Internal Central Links Key Connections to Bearsden

= Scenario 3: Overall improvement of connectivity

Note: These scenarios have been designed so as to have minimal impact on the existing built form and thus only suggest inill street elements that would further develop the area for better result in urban life quality.

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Booklet no.5: Network analysis of streets

Scenario 1 Increasing Local Street Density Kinfauns Dr Ladyload Ave

Blackcraig Ave becomes an important intermediary in the north-south direction as a result of the improved connection between Kinfauns Dr and Drummore Rd.

Linkwood Dr Summerhil Rd

Kinfauns Dr Blackcraig Ave

SCENARIO 1

Drummore Rd

Currently, the existing street network is rather sparse in the area between Linkwood Dr and Summerhill Rd, as well as between Kinfauns Dr and Ladyload Ave. Hence, this scenario proposes a densiication of the streets in these areas in order to tie them into Drumchapel’s overall network and improve the connectivity between places.

Linkwood Dr: Looking north-west

Betweenness Centrality

EXISTING NETWORK

S1: New Links (in red)

Betweenness Centrality

40

Drumchapel

The newly introduced denser grid on the north side of Drumchapel becomes very important in terms of local closeness centrality and introduces conditions suitable for a new urban centre or a neighbourhood core.

Slight improvements in the eiciency of communication within the network are also visible along the north border of Drumchapel, especially in the area between Kinfauns Dr and Ladyload Ave.

Potentially new urban centre

Kinfauns Dr Ladyload Ave

Closeness Centrality at 400m

Straightness Centrality

Closeness Centrality at 400m

Straightness Centrality

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Booklet no.5: Network analysis of streets

Scenario 2 Internal Central Links Key Connections to Bearsden Southdeen Ave

Garscadden Rd

Garscaden Burn Glenkirk Dr

Bearsden

Garscadden Rd Drumry Rd

View over Garscaden Burn

Glenkirk Dr

Betweenness Centrality

EXISTING NETWORK

S2: New Links (in red)

On one hand, this scenario introduces key links within Drumchapel’s network so as to bring together its severed parts. On the other, through a few links on its eastern edge it connects Drumchapel to Bearsden.

New Road (east-west)

SCENARIO 2

Linkwood Dr

The new road connecting Glenkirk Dr and Garscadden Rd becomes an important intermediary route direction and thus creates an east-west axis from Drumry Rd through Glenkirk Dr and into Bearsden.

Betweenness Centrality

42

Drumchapel

In an 800m closeness study, the new northsouth roads (W and E) also seem to be slightly raising the levels of centrality of Linkwood Dr, Glenkirk Dr and Southdeen Ave.

In addition to improving the overall connection, the new road connecting Glenkirk Dr and Garscadden Rd also improves the eicient east-west movement in the network. The new north-south road W introduces a second eicient route, alternative to Kinfauns Drive.

Southdeen Ave Linkwood Dr New Road W (north-south)

New Road E (north-south)

New Road W (north-south) Kinfauns Dr

New Road (east-west) Glenkirk Dr

Drumry Rd Glenkirk Dr

Closeness Centrality at 800m

Straightness Centrality

Closeness Centrality at 400m

Straightness Centrality

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Booklet no.5: Network analysis of streets

Overall improvement of connectivity Garscadden Rd

Linkwood Dr Southdeen Ave Summerhil Rd Glenkirk Dr

Kinfauns Dr Ladyload Ave

Bearsden Drumry

Garscadden Rd

Glenkirk Dr

Bearsden

Drumry

Betweenness Centrality

EXISTING NETWORK

S3: New Links (in red)

This scenario combines both Scenario 1 and Scenario 2 so as to put forward an overall strategy for the amelioration of Drumchapel’s street network which could then potentially create better connectivity and more opportunities for social interactions and urban place making.

Linkwood Dr

Kinfauns Dr

SCENARIO 3

Scenario 3

The denser and more coherent distribution of streets within the network, introduces a central loop between Kinfauns Dr, Garscadden Rd, Glenkirk Dr and Linkood Dr. It then improves the connectivity of the geographic centre of Drumchapel and turns it into an important intermediary between Drumry and Bearsden.

Betweenness Centrality

44

Drumchapel

In the Kernel Density Estimation of the Closeness Centrality at 400m bellow, it is evident that the tight grid proposed on the north side of Drumchapel holds a very central position and is potentially suitable for a new walkable and well-connected civic centre.

Potentially new urban centre

In the comparison of Kernel Density Estimations of the Straightness Centrality of the existing network and the newly proposed, there is also a noticeable increase in the eiciency of network communication in the north of Drumchapel, thus, slightly rectifying the efect of the abrupt turn of Kinfauns Cr on itself.

Closeness Centrality at 400m KDE

Straightness Centrality

Closeness Centrality at 400m KDE

Straightness Centrality

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IV. Conclusion

Drumchapel

This network analysis of streets was conducted in two diferent scales - irst, the global metropolitan context of Glasgow and its west conurbations and second, the local scale of Drumchapel within its immediate surroundings.

Drumchapel

City Centre

2 km

At the wide urban scale, Drumchapel is naturally ofset from the centrality levels of the City Centre areas. The overall infrastructure of the area often circumpasses Drumchapel and thus gives it little importance as an intermediary of communication between diferent urban areas.

The winding nature of the roads leading to and within Drumchapel further decreases the eiciency of travel to and from it. These indings could serve as the starting point should there be any future infrastructural changes so that additional, better and more direct links to the City Centre can be implemented.

At the local scale, due to the challenging topographic conditions in Drumchapel, the street network sufers from an unregulated pattern. Consequently, roads are convoluted and do not facilitate luent eicient movement through the town. Large unoccupied land interrupts Drumchapel’s urban fabric and create big gaps in the street network which then further reduce walkability between one area to the other. The very geographic centre of Drumchapel is serving as a barrier between the north and south parts due to a lack of suicient connections through it. There is an existing network of pedestrian paths in place, yet at places it appears disconnected. The landscape strategy of the green areas can beneit from certain improvements so as to ensure better walkability through the park as a shortcut between Drumchapel’s north and south sides.

This study also puts forward rough suggestions as to how, in principle, the local street system might be improved so as to densify networks in vacant lands severing the town and also add key connections that could improve the connectivity of the existing network to other places.

m 4 km

6 km

k 8 km

Glasgow Metropolitan Area: Regional Network Walkability Markers Administrative Boundary

400m

800m

1200m

1600m

Drumchapel: Existing Street Network and Walkability

Bearsden Drumry

Drumchapel: Proposed New Connections

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Booklet no.5: Network analysis of streets

V. Bibliography Crucitti, P., Porta S., Latora V., Strano E. (2006). ‘Centrality in networks of urban streets.’ In: Chaos: An Interdisciplinary Journal of Nonlinear Science. [Online] Vol. 16, 015113, March.

Available: http://aip.scitation.org/doi/10.1063/1.2150162. [19/10/2017] First UK Bus. (2017). Timetables | Greater Glasgow | First UK Bus. [online] Available at: https://www.irstgroup.com/greater-glasgow/plan-journey/timetables/?source_ id=2&operator=10&service=drumchapel&page=1&redirect=no [Accessed 19 Oct. 2017].

Hillier, B. (1996). ‘Cities as Movement Economies’. In: URBAN Deisgn International. Vol. 1, no 1: 41-60. Cambridge University Press: Cambridge Porta S., Latora V., Strano E. (2010). ‘Networks in Urban Design. Six Years of Research in Multiple Centrality Assessment.’ In: Estrada E., Fox M., Higham D., Oppo GL. (eds) Network Science.

Springer: London Porta, S., Latora, V., & Haas, T. (Ed.) (2008). ‘Centrality and cities: multiple centrality assessment as a tool for urban analysis and design.’ In: T. Haas (Ed.), New urbanism and beyond: designing cities for the future : 140-145. New York.

Porta, S. Latora, V. Wang, F. Rueda, S. Strano, E. Scellato, S. Cardillo, A. Belli, E. Cardenas, F. Cormenzana, B. Latora, L. (2011). ‘Street Centrality and the Location of Economic Activities in Barcelona.’ In: Urban Studies. Vol. 49, no 7, May 2012: pp. 1471-1488 Porta, S. Latora, V. Wang, F. Strano, E. Iacoviello, V. Messora, R. Scellato, S. Cardillo, A. (2007).

‘Street Centrality and Densities of retail and servics in Bologna, Italy.’ In: Environment and Planning B: Planning and Design. Vol. 36, 2009: pp. 450-465 Porta, S. Romice, O. (2016). Analysis brief 05: Network analysis of streets, SPT. (2017). Timetables - SPT. [Online] Available at: http://www.spt.co.uk/bus/timetables/ [Accessed 19 Oct. 2017].

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Department of Architecture University of Strathclyde Glasgow strath.ac.uk/engineering/architecture/