13 Jan 2025 02:26

Isochrone infrastructure study

ANALYSIS

How easy it is to get around Canberra depends upon from where you start the trip. In some places the infrastructure is better than others. One way to study this is with isochrone plots. This article compares the distance one can ride in 60 minutes and 30 minutes from various town centres, testing the ease of cycling in Canberra.

Introduction

How far can you ride on a normal bike in Canberra depends on the quality of the infrastructure – how direct and good it is. The type of bike you ride makes little difference to the travel time. A road bike and electric bike are a bit faster than riding a “normal” city bike and the distances travelled are slightly greater. For mountain bikes the distance may be slightly less, but often more direct routes are available and this style of bike offers better rider comfort. Electric bikes have become very popular as they make the riding easier.

Information box: 20-minute neighbourhoods

20-minute neighbourhoods are an interesting urban planning idea to decentralise the population from the city centres by making the local area more liveable.

The concept is not about travel by car. It is about active transport (walking, cycling) and the use of public transport. The goal is that this combination of modes would offer a reasonably sized catchment area in which people, jobs and services, including recreational opportunities and nature, are accessible.

People love the idea of 20-minute neighbourhoods, The Conversation, 19/2/2020

People generally loved the thought that most (not all) of the things needed for a good life could be within a 20-minute public transport trip, bike ride or walk from home. These are things such as shopping, business services, education, community facilities, recreational and sporting resources, and some jobs (but probably not brain surgery).

Creating a city of 20-minute neighbourhoods is a key policy direction of Plan Melbourne 2017-2050. As the plan states:

The 20-minute neighbourhood is all about ‘living locally’ – giving people the ability to meet most of their everyday needs within a 20-minute walk, cycle or local public transport trip of their home.

People love the idea of 20-minute neighbourhoods, The Conversation, 19/2/2020

Isochrone plot from OpenRouteService

One way to study this question of how far we can ride from any point in Canberra is with isochrone plots. An isochrone plot shows you travel times from a central point. The data is taken from OpenStreetMap and the isochrone plot generated with OpenRouteService. An isochrone plot can be seen for Civic on map 1. The coloured rings show the distance travelled in consecutive 10 minute intervals.

Map 1: 60 minute ride from Civic – 10 min intervals

Legend: distance travelled with a “normal bike”, journey times in 10 minute intervals. The GREEN inner ring represents a 10 minutes journey. The RED outer ring is how far a rider on a “normal” city bike would travel in 60-minute journey.

Map 1: Population data from OpenRouteService. Background map: OpenStreetMap and contributors. Generated by canberrabike

Conclusions: 371,000 people live within a 1 hour ride from civic

Table 1: ACT population living within 60-min ride from civic

Population data from OpenRouteService. Background map: OpenStreetMap and contributors. Generated by canberrabike

Does the type of bike make a difference?

The type of bike you ride makes surprising little difference. The speed we ride and how long we have to stop is dependent on infrastructure and not the bike. The bike infrastructure is a major determinant of travel time.

The second issue, increasing the average speed of a bike takes a great deal of effort with diminishing returns. The inverse relations ship between speed and trip time is the cause (trip time = distance/average speed). Increasing the average speed by 25% from 20 km/h to 25 km/h which is hard to do, and we see only a decrease in travel time of only 20%. The gain is travel time is always less than the increase in average speed. Great speeds mean more acceleration and deceleration – changes of momentum. Commuting to work is a relaxing activity, and racing takes the fun out of it for most people.

Map 2: How far can you get on a bike in 30 minutes?

Legend: Different bike types by colour.

Map 2: Different bike types by colour. 60 minute travel time. Isochrone plot from OpenRouteService. Background map: OpenStreetMap and contributors. Generated by canberrabike

Comparison between town centres

The situation may be better from some town centres as others. Below are isochrone plots comparing the distance travel by a cyclist on a “normal bike” from the town centres of Gungahlin, Woden, Tuggeranong, Civic, and Belconnen.

For the purpose of the comparison, all other things are kept constant. The colours show the distance travelled in 10 minute intervals.

Inner north

Civic

Civic lies the middle of a plain in Canberra’s centre. Not surprisingly, it is easy to get to most places from Civic. We can see this in the isochrone plot for a 30 minutes travel time from Civic centre. We have placed centre close to the ANU. Mitchell, Kaleen, Macquarie, Curtin, Garran, Narrabundah, Fyshwick and Russell are all with 30 minutes with a normal bike from Civic.

Map 3: 30 minute ride from Civic – 10 min intervals
The distance travelled with a “normal bike”

Inner south

Woden

Woden is only 8 km from Civic but much further with a bike due to the poor cycle infrastructure along Adelaide Avenue. Lake Burley Griffin cuts Woden off from Civic and the north. This is the downside of a lake in the centre of a city – it divides the city in two. Still, with Woden at the heart of the Woden Valley, the south part of Canberra is well served. The Canberra north/south split makes Woden all the more important as a town centre as it provides the employment and services that are provided in the inner north by Civic.

Riding from Woden in 30 minutes on a normal bike, a cyclist can ride as far as Chapman, Duffy, Molonglo Valley, Yarralumla, Parliamentary Triangle, Narrabundah, Kambah, Tuggeranong, Gowrie and Macarthur.

Map 4: 30 minute ride from Woden – 10 min intervals, stand 26/1/2020
The distance travelled with a “normal bike”

Far north

Belconnen

Belconnen district is expect to have a population of 120,000 people with 10-20 years and make up about 20% of the ACT population. Belconnen is a rideable distance from Civic – from Belconnen town centre it takes around 30 minutes. For this isochrone plot the centre point has been place to the west of Lake Ginninderra, which favours riding to West Belconnen over riding east to Civic.

From Belconnen town centre in 30 minutes on a normal bike it is possible to ride to Hall, Nicholls, Palmerston, Mitchell, Dickson, O’Connor, Whitlam, Higgins, Holt, Macgregor, Dunlop, Fraser and even the edge of Strathnairn.

Map 5: 30 minute ride from Belconnen – 10 min intervals
The distance travelled with a “normal bike”

Gungahlin

Gungahlin has a population of close to 80,000 already, although it is only 25 years old. Gungahlin lies on the northern plains of Canberra, in the catchment area of Ginninderra and Sullivans Creek. The area is flat and that makes it easy to ride.

From Gungahlin town centre in 30 minutes on a normal bike it is possible to ride to Taylor, Jacka, Bonner, Forde, Throsby, Harrison, Watson, Downer, Lyneham, Kaleen, Lawson, McKellar, Evatt, Spence, Casey and Hall.

Map 6: 30 minute ride from Gungahlin – 10 min intervals
The distance travelled with a “normal bike”

Far south

Tuggeranong

Tuggeranong has a declining population and good cycle infrastructure. The town centre offers employment to many of the locals. We have placed the centre of the map at the west of Greenway on Athllon Drive close to most of the employment in Tuggeranong, including Human Services.

From Tuggeranong Town Centre in 30 minutes on a normal bike it is possible to ride to Fisher, Torrens, Farrer, Macarthur, Gilmore, Theodore, Banks, and Gordon. Woden Town Centre is not in the 30-minute zone.

Map 7: 30 minute ride from Tuggeranong – 10 min intervals
The distance travelled with a “normal bike”