Contrary to the majority of the world's opinion about Australia, the wildlife isn't aggressive or actively seeking out people to hurt. It's the landscape which attempts that (in concert with the weather). The Australian border is pretty much congruous with the Australian coastline - there is no way to drive directly from Australia to another country (and to be honest, given the nearest other countries are right on the edges of geological faultlines, there's really not much of a way to create a safe and/or persistent driveable connection under current engineering constraints, either).