Good and direct bike paths save time

ANALYSIS

Cycle infrastructure is lagging in Coombs. Despite the Concept Plan being finalised in 2012 and the suburb established since 2015, the cycle infrastructure is still not complete or sufficient. As the crow flies, Coombs and Belconnen are about the same distance from Civic centre, however, while commuting from Civic to Belconnen in 30 minutes is possible, it is not from Coombs.

Introduction

Closer proximity between new suburbs and the city helps encourage commuting to work with a bike but the potential benefit of the proximity is largely forfeited without good quality, safe and direct active travel infrastructure. This is currently NOT typical for the Molonglo Valley estate developments in the ACT. Specifically, a comparison using “computer” simulation of travel times on an accurate map of Canberra shows that you are a lot better off living in Belconnen then Coombs. Belconnen`s infrastructure is relatively evenly distributed around the town centre and sufficiently abundant that good progress can be made in all directions. This is not due to the absence of lakes and creeks as Belconnen has plenty.

Analysis and interpretation

How far can you ride on a normal bike from the Coombs in 30 minutes?

The distance depends a great deal on the infrastructure and how direct and good it is. As my analysis has shown, It has less to do with the type of bike you ride. Road and electric bikes are bit better than a “normal” bike and an MTB is slightly worse (but there are more paths to choose from).

Isochrone plot generated with OpenRouteService

An isochrone plot shows you travel times from a central point. In this plot, the green, yellow and red rings are for 10, 20 and 30 minute ride duration. The data is from OpenStreetMap, generated with the software on the website Openroute Service (links below).

What we learn from this

Ideally, with good infrastructure, you could ride the same distance in every direction (with the travel time being held constant). This would make the isochrone plot three circles centre around the origin. This is close to what you get for Belconnen town centre (map 2). But if the infrastructure is poor in one direction the circles are flattened on that side. Also, if there is a lack of direct routes, the line-of-sight distance to your destination becomes less relevant (again, with the travel time being held constant). This means the circles are a smaller radius. This is what you for Coombs (map 1).

Recommendation

One simple improvement that would greatly improve the commuting times to Civic from Coombs would be a bridge across Weston Creek. The approach path and bridge would be a journey of just 250 m. In comparison, if you ride around the Weston Creek Pond (after the paths have been complete) the distance travelled is 2 km.

Visualisations

The isochrone plot shows the distance travelled with a “normal” city bike. The travel distance does not vary much between bike types but road bikes and electric bikes generally travel further when the cycle infrastructure is good.

Legend: colour coding for the following isochrone plots.

• 10-minute journey – green
• 20-minute journey – yellow
• 30-minute journey – red

Travel times from Coombs and Belconnen

Map 1 show the travel distance in 30 minutes for a cyclist starting in Coombs. Map 2 show the travel distance in 30 minutes for a cyclist starting in Belconnen.

Map 1: 30 minute ride from Coombs – 10 min intervals

Map 2: 30 minute ride from Belconnen – 10 min intervals

Infrastructure improvement suggestion

Update 24 February 2022 – Bridge over Weston Creek

A bridge is proposed across Weston Creek between Coombs and the CBR Cycle Route C5 past the RSPCA. The construction of the bridge is expected to begin towards the end of 2022. SLA hopes that the bridge will be completed by the end of 2023. The bridge is as yet to be named.

Map 3: a short bridge makes the city commute from Coombs much shorter. Source: OpenStreetMap 2020

Below, the overview map showing the difference between the direct line-of-sight path and the grey lines show the actual grade separated bike path route. The bike path is rarely the most direct route but the safest and much preferred to riding on the road. Most people are prepared to ride a bike on a grade separated bike path but only a few percent (3% in the ACT) consider the road as the option.

Map 4: Coombs and Belconnen to Civic – line-of-sight and actual travel routes

Data sheet

Line-of-sight distances versus actual distance to Civic

Summary table for the analysis compiled by canberrabike

Note 1: The straight-line-distance between the two points is always the shortest (most direct) path (see map 4).

Note 2: The “actual cycle distance” is calculated using cycle maps from OpenStreetMap (2020) and Garmin autorouting software (see map 4).