Horse Park Drive Duplication

Dr Kate Auty - Commissioner for Sustainability and the Environment - 10 June 2016

View of Horse Park Drive proposed duplication


Thank you for the opportunity to comment on the planned duplication of Horse Park Drive as part of the community consultation process. I understand that the ACT Government has committed $57 million to upgrade Horse Park Drive in order to improve safety, traffic flow and to provide better access to nearby suburbs, including the new suburb of Throsby. This appears to be a prudent investment to alleviate current and future congestion in the area.

My comments at this stage of the project are mainly in relation to aspects of the project design. However, I take this opportunity to flag the need to consider effective management during the construction phase as well.  Consistent with my role as Commissioner for Sustainability and the Environment, my comments address the following aspects of the project:

  1. Background
    1. Congestion and the case for investment in active transport infrastructure
    2. Water Sensitive Urban Design (WSUD)
    3. The influence of a warming climate on commuter travel preferences
  2. Developing a sustainable transport system for the future
    1. climate mitigation meastures for active transport
    2. amenity measures for active transport
  1. Implementation of Water Sensitive Urban Design (WSUD)
  2. Managing construction impacts
1. Background

a)      Congestion and the case for investment in active transport infrastructure

Infrastructure Australia commented in its Australian Infrastructure Audit Report that ‘congestion in our cities is perhaps the area with the greatest gap between what we expect from our infrastructure and what is delivered’.[1] The report calculates the cost of Canberra’s congestion to be $208 million in 2011, and estimates that figure to grow to $703 million by 2031 if further investments in transport infrastructure are not made.[2] Clearly these costs should be avoided, and so infrastructure investments must be made accordingly.

These investments should address the alleviation current and future congestion. It has become apparent in recent years that merely building more of the same - larger, better roads - is not a viable long term solution for developing effective commuter transport networks in our increasingly populous cities. Increasing the availability and quality of alternative transport is crucial to ensuring we minimise various costs to Canberrans.  Economic , social, health and environmental costs posed by congestion can all be minimised if investment in active and public transport networks is prioritised.

Active transport has many benefits, however commuters will only change their behaviour if the transport infrastructure supports them to do so. It has been observed that ‘higher levels of bicycle infrastructure are positively and significantly correlated with higher rates of bicycle commuting’.[3] Additionally, investment in active transport infrastructure that enhances amenity or overall quality is likely to ‘benefit users directly, and... society overall, including people who do not currently use walking and cycling facilities’.[4]

The case for investment in active travel infrastructure is further strengthened when considering the return on investment. It has been estimated that investment in cycling infrastructure can expect to return up to ‘$3.88 for every dollar spent - in net economic benefits over 30 years’, a significantly higher return than for typical road infrastructure projects ($2.70 per dollar spent).[5] [6] The costs for delivering cycling and shared paths is also substantially lower in absolute terms; the Queensland Government estimated that the ‘average cost of a typical off-road path is around $1.5 million per kilometre’, as compared to the $22.5 million currently invested in the ~2.5 kilometre duplication of Horse Park Drive.[7]

b)      Water Sensitive Urban Design (WSUD)

Water Sensitive Urban Design (WSUD) is a planning and design approach aimed at integrating ‘water cycle management and ’green’ infrastructure (vegetation and water bodies) into urban planning to slow runoff, ameliorate flooding, and reduce pollutants and sediment entering waterways’. [8]

Banksia St Wetland

Stormwater runoff is treated in this small wetland at Banksia St, O'Connor.

The importance of ensuring Canberra’s urban landscape is water sensitive has been highlighted in recent years by drought, and will become increasingly important as the ACT is expected to experience more extreme rainfall events that have the potential to result in flooding, hazards for commuters, damage to infrastructure and adverse impacts on water quality in the city’s lakes and ponds.[9] The design of our urban infrastructure must keep pace with our changing environment to avoid the worst of these impacts.

c)      The influence of a warming climate on commuter travel preferences

Commuters are less likely to use active modes of transport in hot or very hot weather. One study found that, of all weather variables, ‘very hot’ temperatures of over 30 degrees Celsius were the most influential in reducing pedestrian and cyclist numbers.[10] The negative impact of hot weather on active travel user numbers is likely to become more pronounced as the expected impacts of climate change come about - the number of hot days over 35 degrees Celsius that Canberra experiences annually is expected to increase from 5 days to up to 10 days by 2030.[11] Commuters switching from active transport to other modes during days of extreme heat may also lead to a spike in demand and strain on those services at times when they are already under stress.[12] Clearly the negative impacts of climate change on travel modes will need to be addressed if the ACT Government intends to achieve the targets stated in the Transport for Canberra strategy.

Cyclist rides next to Sullivans Creek

Cyclist rides under Canberra urban forest canopy near O'Connor.

2. Developing a sustainable transport system for the future

I note that while the current consultation details the layout of on-road cycle paths, bus stops and off-road shared paths, it does not specify what additional infrastructure will be developed to support active transport options.

A number of steps should be taken to ensure Canberra’s transport network remains functional in a future climate scenario of increasing extreme heat. These include actions to mitigate against expected climate change impacts, and actions to improve patronage of sustainable transport options. I discuss a number of these actions below.

a) Climate mitigation measures for active transport

Investment in Canberra’s urban forest to create shade along cycling and shared paths is an important step in mitigating the effects of climate change. The Horse Park Drive duplication should make use of urban forests as they provide a number of benefits to individual users and the broader community:

  • Shade is highly desirable for cyclists and pedestrians in order to use paths in comfort. Trees planted in close proximity to cycling paths and shared paths can have a considerable impact on local ambient temperatures, with shade and evapotranspiration provided by trees on hot summer days helping to reduce localised temperatures by up to 5 degrees Celsius.’[13][14]
  • Trees also provide shelter against wind. Exposure to wind has been correlated with reduced active transport user numbers.[15]
  • Planting of trees alongside shared paths can also reduce long term maintenance costs of infrastructure; ‘Urban forests that provide significant canopy coverage improve the lifespan of certain assets such as asphalt by shading them from harmful UV rays – potentially by 30%’.[16]
  • Trees also positively contribute to the landscape character, providing visual amenity for local residents and commuters.
  • A healthy urban forest contributes to biodiversity and habitat provision. Urban forests around the world have been shown to support a wide range of species, even endangered animals and other species of high conservation value.[17]

2. b) Amenity measures for active transport 

To further support active transport users, the ACT Government should consider extending its water fountain and water bottle refilling station program to the Horse Park Drive duplication. Placement of one or more stations along shared paths is likely to increase the attractiveness of these paths for commuters and leisure users.

Secure bike storage for commuters wishing to use public transport options should also be made available for those wishing to ‘Bike and Ride’. Co-location of bike storage facilities with bus stops and Park and Ride stations should be considered as this would be strongly aligned with the objectives of the ACT Government’s Active Travel Framework and Transport for Canberra Strategy that seek to increase use of sustainable transport options.

Bus travel park and ride in Gungahlin

Park and ride facility, Flemington Rd, Gungahlin. 

The ACT Government should consider widening of the shared paths, as path width has been identified as ‘a critical element to minimise conflict between cyclists and pedestrians’. [18] The ACT Government’s Municipal Infrastructure Standards (Part 5 Design Draft 4) states that ‘trunk path’ width should be 5m where there is ‘high levels of pedestrian and cyclist use in both directions, commuting, [at] speeds greater than 30km/h’.[19] The planned shared paths should be widened to adhere to this design standard.

Interpretive and navigational signage, including along shared paths, should be included in development as this will improve connectivity across the transport network. This signage could:

  • Promote local recreational sites (community facilities such as parks, wetlands, Centenary Trail etc.) by indicating their location and distance, and by providing a brief description of each location of interest.
  • Mark distances and estimated travel time to nearby group centres, transport nodes and facilities to assist active travel commuters (ie. X minutes by bike, Y minutes by foot). This signage could take the form of on-ground stencils or other creative means.

I note that the current Horse Park Drive design document provided on the TimeToTalk webpage shows only partial implementation of green paint ‘conflict markings’ for cycle lanes at the Katherine Avenue intersection – the slip-lane on to Katherine Avenue has not been marked in green. The green road markings should be extended to this slip-lane to ensure consistency and safety for on-road cyclists.

Water Refill Station

Water refill station at the Australian National Botanic Gardens.

3. Implementation of Water Sensitive Urban Design

The Horse Park Drive project will add several kilometres of impermeable surfaces which will, in the absence of adequate water management measures, contribute to stormwater ‘pulsing’ during rain events. Such surfaces can also act as a collecting point for various potential pollutants including litter, sediment and suspended solids, toxic organics, nutrients, heavy metals, and hydrocarbons’.[20] The ACT Government should detail how it plans to employ WSUD to minimise the impact of the Horse Park Drive project on established waterways such as Gungaderra Creek and Wells Station Creek.

A number of WSUD designs could be implemented along Horse Park Drive. These include;

  • Reed bed filtration and grass swales to manage water runoff, particularly into Gungaderra Creek and Wells Station Creek.
  • Rain gardens (also known as bio-retention basins) located at the two proposed Goorooyarroo Nature Reserve parking sites.
  • Gross pollutant traps such as drain baskets, trash racks and pipe nets.

However, before WSUD is implemented a thorough investigation should be made of aquatic plant and animal communities that may be impacted by the planned development and a plan developed detailing how these communities will be managed.

4. Managing construction impacts

Acknowledging that the scope of the consultation is limited to design features, I provide the following brief comments in relation to construction. In particular I note the potential for some of the structures created during construction to remain in-situ once works are completed, thus becoming part of the final design. Construction activity may also impact on existing design features – these should also be considered.

I note the presence of several existing WSUD landscape features, including swales and small wetland areas, directly adjacent to the north-running section of Horse Park Drive. Given the significant construction activity generated by the duplication works and the Throsby development, there is likely to be sediment run-off which may adversely impact on these features if controls are not adequate.

The ACT Government should take a proactive position in protecting these assets, as it has previously acknowledged that there is a ‘need for improved levels of compliance and more systematic monitoring of erosion and sediment controls during land development and construction’.[21] The ACT Government should ensure that construction sediment control practices such as sediment traps are 

in place to protect waterways during construction, and sites are quickly re-grassed to prevent erosion of newly formed batters.

Thank you again for the opportunity to comment on the designs for the Horse Park Drive Stage 2 duplication.


[1] Infrastructure Australia, 'Australian Infrastructure Audit Report' (Infrastructure Australia 2015).

[2] Ibid.

[3] Jennifer Dill and Theresa Carr, 'Bicycle Commuting And Facilities In Major U.S. Cities: If You Build Them, Commuters Will Use Them' (2003) 1828 Transportation Research Record: Journal of the Transportation Research Board.

[4] Victoria Transport Policy Institute, 'Evaluating Active Transport Benefits And Costs: Guide To Valuing Walking And Cycling Improvements And Encouragement Programs' (Victoria Transport Policy Institute 2013).

[5] Australian Bicycle Council, 'National Cycling Strategy 2011-2016.' (Austroads 2011).

[6] Bureau of Infrastructure, Transport and Regional Economics, 'Infrastructure, Transport and Productivity' (Department of Infrastructure and Regional Development 2014).

[7] Department of Infrastructure and Transport, 'Walking, Riding And Access To Public Transport: Supporting Active Travel In Australian Communities,' (Department of Infrastructure and Transport 2013).

[8] ACT Environment and Planning Directorate, 'ACT Water Strategy 2014-44: Striking The Balance' (ACT Government 2014).

[9] ACT Environment and Planning Directorate, 'Draft ACT Climate Change Adaptation Strategy - Living With A Warming Climate.' (ACT Government 2016).

[10] 'Impact Of Weather On Commuter Cyclist Behaviour And Implications For Climate Change Adaptation', , Australasian Transport Research Forum (Australasian Transport Research Forum 2010).

[11] ACT Environment and Planning Directorate, ‘Draft ACT Climate Change Adaptation Strategy’

[12] Ben Westcott, 'ACTION Bus Network Disrupted By Extreme Heat' (Canberra Times, 2014) <> accessed 10 June 2016.

[13] City of Melbourne, 'Urban Forest Strategy' (Victorian Government 2012).

[14] Victorian Centre for Climate Change Adaptation, 'Responding To The Urban Heat Island: A Review Of The Potential Of Green Infrastructure' (Victorian Centre for Climate Change Adaptation 2012).

[15] 'Impact Of Weather On Commuter Cyclist Behaviour And Implications For Climate Change Adaptation', Australasian Transport Research Forum (Australasian Transport Research Forum 2010).

[16] City of Melbourne, 'Urban Forest Strategy' (Victorian Government 2012).

[17] Ibid.

[18] Centre for Road Safety, 'Shared Paths' (NSW Government 2015).

[19] ACT Territory and Municipal Services Directorate, Municipal Infrastructure Standards Part 5 – Active Travel Facilities Design – Draft Revision 4' (ACT Government 2016).

[20] Austroads, 'Road Runoff & Drainage: Environmental Impacts And Management Options' (Australian Government 2001).

[21] ACT Environment and Planning Directorate, 'ACT Water Strategy 2014-44: Striking The Balance' (ACT Government 2014).

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