Koalas are territorial creatures, however they have large home ranges, and will travel long distances to find breeding partners, or in the case of young Koalas, to find a new territory to move into. This often brings Koalas into conflict with roads, especially in the Sydney Basin with so many cars using these roads. Sadly most roads in Sydney have not been built with wildlife in mind. And unfortunately Koala deaths are viewed as a cost of doing business, rather than a state responsibility.

Many of the roads that intersect where Koalas live in Sydney are arterial roads, which are large roads that link outer suburbs together, often at higher speeds, which is why they are so fatal for Koalas. Already this year 50 koalas have been killed on roads in the in the South West of Sydney (Bionet 2024), with arterial roads such as Appin Road (21), Heathcote Road (11), Hume Highway (3) and Picton Road (2) responsible for the majority of these deaths, risking sending this vital disease free population into decline. 

All these roads are at least 80 kilometres per hour (or more) which is fatal for Koalas. When looking at Koala deaths, often it is very obvious where Koalas are being funnelled into the road. It is usually only short stretches of road where Koalas are most likely to cross, which is why we're adamant that these short stretches (where there are no wildlife crossings) should have speed limit reductions. 

Reducing speed, especially across Koala corridors, greatly improves Koala safety and reduces fatalities. At 80 km/h the impact is almost always fatal. Safe speeds are based on the following criteria.

• Impact Energy: The energy transferred to the koala is pr
  oportional to the square of the speed, so even a small reduction in speed significantly reduces the force of the collision.
• Reaction Time: At lower speeds, drivers have more time to react and brake, which can either reduce the severity of the collision or avoid it altogether (NSW Government 2020).
• Survival Rate: As speed decreases, the likelihood of the koala surviving increases dramatically, and injuries tend to be less severe.

According to the NSW Government calculations for stopping distances:
If you see a koala on the road 40 metres ahead:

• Travelling at 80km/h:
  • You will not have time react before hitting the koala
  • Impact energy = very high
  • Likely outcome = dead Koala 

• Travelling at 60km/h:
  • You will have time to react and potentially avoid the collision
  • Impact Energy (if hit) = reduced by more than 2 fold.
  • Likely outcome = greater chance of survival for the Koala

• Travelling at 40km/h:
  • You will have time to come to a complete stop 
  • No impact
  • Likely outcome = Koala survives

In a 50 km/h zone, you could stop safely within 40 metres. However, at 80 km/h, you would need to see the Koala at nearly 100 metres to stop in time.

Last week Campbelltown Council unanimously voted to write to the State Government and ask for the 50 zones on Appin Road to be extended in the areas where Koala corridors cross the road (Noorumba, Beulah, and Mallaty Creek). We whole heartedly agree.

Unfortunately the Roads Minister John Graham has recently publicly stated travel time is more important than further endangering threatened species. These three Koala corridors would literally be seconds in difference in travel time. These Koalas have a limit to how many can be killed before the population is sent into a spiral of decline. They are reaching their limit, and we must reduce our speed limit in order for them to be saved from extinction. 

Image: Location of Koala Corridors in Campbelltown (Biolink)