Taking the blinkers off rural road safety – how wildlife vehicle collisions can be minimised
In the fifth article in the series ‘Wildlife road kills versus Vision Zero 2050’ freelance journalist Patrick Francis explores some existing initiatives which provide transport department engineers and planners with an avenue for including wildlife in rural roads crash risk assessments and provide equity for all road users.
The Austroad Infrastructure Risk Rating (IRR) Manual for Australian Roads is used by all state government roads’ managers for road risk assessments. It gives engineers the tools to make road risk assessments calculated by coding roadside features like adjacent land use, roadside hazards and specifically, on rural roads traffic volume and speed limit.
Given 50,000 or more insurance company wildlife vehicle collision claims each year and single vehicle run-off road crashes on regional and rural roads are the major cause of vehicle occupant fatalities and serious injuries it would be reasonable to assume that wildlife on roads would be considered relevant for assessing road risk but there is no reference to wildlife anywhere in the manual.
The Austroads Infrastructure Risk Rating (IRR) is a road speed safety risk assessment methodology that is calculated by coding the following road and roadside features. All the state road management authorities use the same road attributes:
• Land use
• Road stereotype
• Lane and shoulder width
• Horizontal alignment
• Roadside hazards
• Intersection density
• Access density
• Traffic volume – rural roads only
• Speed limit – rural roads only.
These features suggest that IRR is based only on road physical factors an engineer can measure. For instance the manual refers to roadside hazards such as verge trees in terms of their number and trunk diameter. Trees (greater than 10cm diameter) must be present at a density of 20+per kilometre and less than 5m offset from the road edgeline to be considered a severe hazard category. If the tree trunks are less than 10cm diameter irrespective of their offset from the road edgeline their risk rating is low.
In the event that tree numbers vary over a section of the road the Manual advises an average hazard category should be selected. It provides an example “For a flat, straight road with occasional trees (less than 20 per km) that are 5-10m from the edgeline, then the roadside hazard category alternates between ‘Moderate’ (where there are trees and poles) and ‘Low’ (where there are no hazards). The average category that should be selected is ‘Minor’”.
To determine the “safe” speed for a road Transport departments add a crash risk rating (CRR) to the Infrastructure risk rating (IRR). The CRR involves compilation of crash data for the road speed zone under review collected over the most recent five year period, figure 1. No wildlife vehicle wildlife collision data from insurance companies and wildlife rescue agencies is considered in the formula for making a road crash risk rating despite the fact that these sources can identify wildlife vehicle collision hotspots.
Figure 1: The current Safe System principles used for determining crash risk assessed speed limits for Australia’s posted and default high speed rural and regional roads do not have wildlife included in the Infrastructure Risk Rating and Crash Risk Rating, so they are ignored as a risk to vehicle occupants. Source: Kangaroo dash cam Youtube; wombat dash cam Patrick Francis
Given the transport departments that use the CRR to determine safe speed are also responsible for placement of wildlife warning signs along rural and regional roads it is surprising that the number of these signs along a stretch of road are not included in the crash risk rating formula. The signs were erected in the first place as a warning to drivers that wildlife crashes are a risk.
Figure 2: A road’s crash risk rating is calculated using a formula that does not include data about each road’s wildlife vehicle collisions as these are not collected by any state Transport Department to input into the formula’s At “number of crashes in DCA Group t over a five year period”. Even data from insurance company animal vehicle collision claims or wildlife rescue agencies reports is not considered as a possible alternative for At. Source: Queensland TMR Road Safety Technical Users Volumes August 2023
Such a formula based quantitative calculation for crash risk rating roads must ignore wildlife as their presence on the verge, on the road and in adjacent paddocks is unknown and unpredictable. Run-off road crash data does not include “swerve to avoid wildlife” (see figure 5 Run-off road crashes in Australia 2016 – 2020 BITRE in article 2) so that cause for crashes seems to be ignored by road engineers as well when making road speed limit decisions. So rather than include unknown wildlife as being a risk to vehicle occupants the assessment of road risk using two quantitative data sources IRR and CRR ignores them completely.
Another example of how engineers use readily available road traffic data rather than requests by local road users is provided by correspondence from a central Victorian peri-urban shire council engineer responding to a local’s request for removal of the 100km/h default speed limit. The lane in question originates on a local town boundary and provides access to farms. The construction of a housing estate within the town boundary has resulted in town residents using the lane as pedestrians and cyclists for exercise and to enjoy the habitat and biodiversity occupying the adjacent farm land, figure 3. The revegetation adjacent to the lane has resulted in a return of large number of native animals to the area but these are being regularly killed by vehicles.
Figure 3: A real life example of how a local council engineer uses vehicle and driver centric data rather than published pedestrian probability of fatal injury data and social equity to conclude that pedestrians/cyclists are safe sharing a default 100km/h lane with vehicles. The decision tree used to reach such a conclusion ignores the welfare of pedestrians and cyclists and even local road users who put up with road rage for travelling at a 30 – 40km/h speed which is a safe speed for the unprotected road users and wildlife. As for wildlife safety, that is completely ignored by engineers who have no jurisdiction over their welfare on roads. Sources: Table – Austroads 2014; Figure – Engineers Australia 2024; Photos – Patrick Francis.
Based on the Safe System Speeds and Engineering Australia’s advice for roads used by pedestrians and vehicles and lined with trees and poles, the maximum speed limit for the lane is 20 – 40km/h to avoid an extreme probability of a fatal collision, figure 3.
Rather than take any notice of potential fatality rate data from these two respected sources the council engineer used a set of road specifications which are entirely vehicle and driver mobility centric. These are:
Traffic Counts –Based on 2020 traffic counts, a total of 115 vehicles per day travels on the Lane and peak hours volume is 13 vehicles
85th percentile speed limit- Based on 2020 traffic data, the 85th speed limit has been recorded as 78.56km/h.
Crash History Analysis of the Road- Based on the past five years from 2017-2021, no crash has been reported on the lane.
Number of access points along the route – 3 access points along the route.
The nature of the road environment- Road is classified as rural and surrounded by farms.
Adjacent speed zone- 80 km/h on (north end road opposite the estate) Road and default 100km/h on (south and east) Roads with no evidence of speed limit being exceeded.
The engineer concludes “Based on the above evidence, information and Victorian speed zoning guidelines, Council Engineering Officers advise that the Lane does not meet the criteria for a speed reduction.”
This is a classic example of ignoring what Engineering Australia contends needs to be injected into transport policy, planning and design, and that is equity. The peak body states “An equitable approach (to road safety) is about continuing to learn about who has what needs, working to meet them and providing accordingly.” The Council engineer’s decision to maintain the default 100km/h speed on the lane in question ignores the safety of pedestrians and cyclists and other drivers prepared to drive slowly while rewarding the mobility of drivers prepared to travel at speed in excess of what is safe in the event of a collision.
The issue of impacting mobility has been raised by Infrastructure Victoria in its draft 30 year infrastructure strategy where it proposes reducing speed limits to 30km/h on local suburban streets that encourage walking and cycling. The strategy recommends the AustRoads Safe System Speeds (Figure 3) and notes “Slower speeds make streets safer. They have little effect on travel times by car.”
So the council engineers concern about vehicles drivers’ ‘mobility’ that is, the ability to reach a destination as quick as legally possible should in fact be insignificant compared to the fatality risk to pedestrians and cyclists on the same lane.
The failure to accommodate wildlife vehicle collisions in the IRR and CRR – the basis for all Australia’s State and Territory Road Safety Strategies 2021 – 2030 , is why road engineers can ignore requests to reduce the speed limit along roads through wildlife hotspots. It’s why some USA researchers are questioning the Safe System’s engineering approach to road safety solutions adopted by all of Australia’s government road management and safety agencies.
Data supplied by range of agencies evaluating fatalities and serious injuries on Australia’s regional and rural roads demonstrates all state strategies are failing to meet their objectives and suggests the Safe System needs to evaluate additional factors other than engineering and historic crash data for determining safe speeds for rural and regional roads, figure 4.
Figure 4: Australia’s Road Safety Strategies 2021 – 2030 based on the Safe System principles using quantitative road infrastructure, crash data and technology developments are failing to meet road fatality death objectives in all jurisdictions so additional holistic strategies need to be added. Given there were about 50,000 wildlife vehicle collision insurance claims in 2023, wildlife are contributing to occupant deaths and injuries directly and indirectly in run-off road crashes. Source: Graph Australian Automobile Association.
But there are possible solutions if state and territory transport department ministers can be sufficiently motivated to embrace a holistic Vision Zero 2050 and demand wildlife in the vicinity of roads are assessed by road ecologists, wildlife rescue professionals and adjacent land owners and included in road risk and speed assessments. This will require road transport department engineers to develop risk assessments in conjunction with people and organisations with local wildlife knowledge.
There are ways to accommodate wildlife risk on roads in the Safe System and Federal and State road safety strategies despite the fact that “..wild animals in Australia can be largely unpredictable. That’s why drivers should always expect the unexpected when driving on the road, particularly at dawn and dusk. This is especially true in areas where kangaroos inhabit because they are the most at-risk animals when it comes to being hit by cars”.**
Road Effect Zone
In contrast to Austroads ignoring wildlife, the Queensland TMR has introduced a way of evaluating the impact of vehicles on wildlife living adjacent to roads by calculating a Road Effect Zone (REZ) for wildlife species. It defines the REZ as “the distance or area over which the combined impacts of the road extend into the surrounding landscape and impact fauna”. It is measured as the abundance of fauna away from the road and is always wider than the road itself, figure 5.
Figure 5: The Queensland TMR recognises a Road Effect Zone for evaluating vehicle impacts on wildlife which extends far beyond the road reserve but does not use it as a tool to help estimate wildlife vehicle collisions potential for vehicle occupant deaths and injuries. Source: QTMR Fauna Sensitive Transport Infrastructure Delivery Chapter 4 October 2024
According to TMR wildlife vehicle collisions or road kills contribute to the REZ by reducing population sizes and/or lowering population densities in the area around the road. It states the road acts as a ‘sink’ or killing zone for local wildlife populations over long distances from the road itself.
The REZ is calculated by approximating the distance that road kills extend from the road into surrounding habitat and by monitoring wildlife road kills. The size of a REZ will vary among species with TMR suggesting it can extend up to one kilometre for birds and five kilometres for mammals. This is a critical calculation for road transport departments to consider when risk rating roads especially given the increasing number of nature repair and carbon market projects being undertaken by landholders whose properties are adjacent to roads. Such projects are designed to increase wildlife populations across the area involved and the REZ accommodates this.
Figure 6A: This revegetation program on pasture land and bordered by two 100km/h speed limit roads is not considered in the Austroads crash risk analysis for the two roads. Its analysis ignores any risk to vehicle occupants’ safety from potential wildlife vehicle collision when animals enter and leave the revegetated area. Photo: Patrick Francis
Figure 6B: The same revegetation program with Road Effect Zone calculated to assess the risk of wildlife vehicle collisions on the two boundary roads and the impact of road kills on the resident wildlife population which should be increasing as the replanted habitat improves. Photo and design: Patrick Francis.
Even within the Department of Transport and Main Roads wildlife road safety risk assessment, Safe System engineering considerations neglect wildlife when determining a safe vehicle speed. The TMR’s ‘Guide to Speed Management’ August 2023 provides engineers with a “Speed Limit Review Checklist Form” as a decision tree for changing vehicle speed on a road. Despite TMR developing the Road Effect Zone to account for wildlife vehicle collision risk it is not included as a crash risk on the checklist form. However, it does include “Hit Animal” as one of at least 21 types of crashes.
The Guide to Speed Management has a section where “the engineer should consider if there are other circumstances which exist that should be taken into consideration (for changing the road speed limit)” with the example given of wildlife activity on the road. Even here the Road Effect Zone is ignored.
A spokesperson for TMR confirmed this stating, “The Road and Rail Effect Zone (REZ) …is a concept specific to the Fauna Sensitive Transport Infrastructure Delivery (FSTID) manual. The FSTID manual, including the REZ, is a tool to consider the impact that linear infrastructure has on native fauna; not a tool to consider the impacts of wildlife (native or exotic) on road users”.
Queensland’s TMR describes why each native species group is killed in wildlife vehicle collisions (WVC). In its Fauna Sensitive Transport Infrastructure Delivery research document, the chapter about macropods states “Many studies have attempted to identify the factors contributing to rates of increased wildlife vehicle collisions (WVC), and a consistent theme is the positive relationship between habitat quality and macropod population density. In other words, there are generally higher rates of macropod WVC in areas supporting more individuals. Traffic speed is also an important factor, with generally higher rates of WVC occurring as traffic speed increases. There is also a correlation between the timing of traffic and rates of WVC, including peaks at dawn and dusk for both vehicles and trains”.
Despite this knowledge about wildlife vehicle collisions it is not used for setting speed limits on Queensland’s rural and regional roads. TMR engineers use formulas to determine road infrastructure risk ratings and crash risk ratings that are not based on habitat quality on private land adjacent to roads, that is, within the Road Effect Zone.
Darryl Jones makes reference to the Road Effect Zone in his road ecology book ‘A Clouded Leopard in the Middle of the Road’ . He states the Road Effect Zone “is crucial because it forces us to think well beyond the road and the vehicles, to become aware that the influence of traffic extends outward and has many consequences”.
He elaborates citing a European method of quantifying how roads fragment a landscape called mesh density and effective mesh size. In its simplest form effective mesh size is the average area available to an animal without it having to cross any roads. As mesh size decreases the likelihood of wildlife vehicle collision increases. The collision situation becomes worse as landholders within a mesh introduce nature repair programs to provide more habitat to encourage wildlife to return to their properties.
The Road Effect Zone was included in University of NSW research by Dr Daniel Ramp in the early 2000s. In 2002 he said Australia had 810,022 km of road and the wildlife affect of the road is further reaching than the road strip itself. ”Calculations of the road effect zone must take the impacts of chemical and noise pollution, the avoidance response of wildlife and habitat alteration into consideration”.
Ramp contends that at its simplest, the road effect zone extends 200m from the road verge and on that basis “we can derive a total of 162,004 km2 of road effect zone in Australia, or 2.12 % of the Australian landscape. In New South Wales there is 182,006 km of road, divided almost equally between bitumen or concrete roads and gravel or crushed-stone roads. We can then predict that just over 4.5 % of land in New South Wales can be considered within this very conservative estimate of effect zone.”
Accounting for Nature® Standard
Another opportunity for Austroads to include wildlife vehicle collisions in its road risk rating methodology is for local and state governments to participate in the Accounting for Nature® Standard’s Econd® Index.
Figure 7: A modified version of Accounting for Nature® Standard could be adopted by all government environment agencies, Transport departments and local councils to develop wildlife based indicies to rate and track change in the animal vehicle collision risk on any road in Australia. Source: Accounting for Nature Standard.
Econd® is short for ‘environmental condition index’, and is the core metric used in all Asset Accounts. ”It is an index between 0 and 100, where 100 represents the Condition of an Environmental Asset in its undegraded (natural or best-on-offer) state.”
Econd® could be possibly modified for assessing threats to wildlife on roads and included in the Austroads Road Risk Assessment tool. The un-degraded wildlife road condition state is zero deaths from road kills to give a 100 point rating. Road kills threat will be based on assessment of adjacent roadside but more importantly adjacent land vegetation type and condition and adjacent water features – dams, creeks which encourage wildlife proliferation and movement and threatened species assessment. Combined with a wildlife vehicle collision modified Road Risk Assessment and Crash Risk Rating, Transport departments could have an ongoing holistic methodology for implementing decisions around appropriate legal speed limit for any particular road or section of road.
Figure 8A: The Accounting for Nature Econd® index could be used to rate wildlife assets adjoining roads and the threats to them so an ongoing trend based on ecological science is determined ensuring vehicle speed zoning is appropriate for the asset’s condition. Source: Amanda Hannson Landcare Farming webinar 6 November 2024.
Figure 8B : If adoption of the Econd® index or Road Effect Zone (REZ) was adopted by this local government shire in central Victoria it’s engineers may have prevented many wildlife vehicle collisions by understanding the wildlife movement implications associated with gradual change in land use then removing an inappropriate speed limit. For example this property changed from 100% pasture in 1990 to a protected riparian zone with biolinks over 35 years to become a wildlife hotspot in 2025. The lane’s historic default 100km/h speed limit associated with no wildlife is no longer appropriate based on the Safe Systems Speeds and lower kinetic energy transfer in crashes to vehicle occupants so they are less likely to be injured or killed. Protection of wildlife would also be enhanced by Safe System Speeds and vehicle damage insurance claims and repair costs reduced. Photos: Patrick Francis, aerial Google Earth.
The inclusion of an Econd® index and/or Road Effect Zone into the Safe System approach to road safety used by all state Transport departments broadens the effectiveness of the methodology to produce positive road safety and environmental asset outcomes which have a chance of achieving Net Zero 2050 in much the same way the Safe System Pyramid is being promoted to take social consideration into road safety risk assessment.
Transport for NSW has developed a Transport Biodiversity Policy which commits it to “protect and enhance biodiversity with the goal of achieving no net loss of biodiversity” as a consequence of building new roads. The policy makes no mention of any strategies to reduce wildlife vehicle collisions and road kills on the state’s 220,000 km public road network. Yet it admits its road network “often contains important biodiversity that is rare in the surrounding landscape and can provide the habitat connectivity needed to maintain viable habitats overtime”. The only reference to wildlife injury in the policy relates to minimising vehicle strikes during road construction.
Figure 9: There are no ways to accommodate wildlife vehicle collisions within the Safe System Model adopted in all Road Safety Strategies 2021 – 2030 but Australia’s roadsides have tens of thousands of wildlife warning signs installed and tens of thousands of vehicles collide with wildlife each year. Sources: Safe System Model Queensland TMR; photos Patrick Francis.
Take home message
The Austroads road risk rating assessment methodology is locked into driver behaviour, driver mobility and vehicle centric engineering approaches to achieving lower road casualty objectives. This means wildlife contributions to crashes are outside Transport department engineers’ jurisdiction and are therefore not considered. As its stands now, the Safe System Model supported by Austroads and adopted by all state and territory governments treats causes of road crash casualties as if Australia is devoid of wildlife, so practical and humane ways of including unpredictable wildlife as a contributor to casualties can be ignored.
Next article:
Wildlife road kills outside Environment departments’ jurisdiction to act so ignored
References:
Engineers Australia and Transport Australia Society “Towards safer and more liveable urban streets” Discussion Paper, December 2024
** What’s My Claim Worth Personal Injury Legal Panel | Expert Representation – WMCW
Australian Automobile Association Analysis Benchmarking the Performance of the National Road Safety Strategy September Quarter 2024
Queensland Road Safety Technical User Volumes (QRSTUV)
Guide to Speed Management August 2023
Austroads Infrastructure Risk Ranting Manual for Australian Roads March 2019.
Darryl Jones ‘A Clouded Leopard in the Middle of the Road’ 2023.
Accounting for Nature® Standard.
Accounting for Nature Regional-Scale Native Vertebrate Fauna Method.
QTMR Fauna Sensitive Transport Infrastructure Delivery Chapter 4 October 2024.
