Minimal collision risk over Alice Springs. Again another demonstration of gross ignorance. Everything to and from SEA Asia for ML, SY & AD goes over or close to Alice plus DN overflyers. With scheduling they all get there about the same time. I did procedural enroute from Alice tower in the 80s and 90s and it was bloody hard then and it didn't take long to run out of airspace when working with converging tracks, 20 DME or 2000 ft separation. About three o'clock one morning SY fogged in and I had six overflyers heading that way. Try handling those diversions procedurally.
The number of airlines and traffic to Asia has increased significantly since then and is forecast to grow. Aircraft nearing Alice will have burnt off a fair bit of fuel and possibly looking for higher levels. Add to that RVSM and free flight and procedural control over Alice is still flat out.
ADS-B will ease workload, free up airspace, allow aircraft to fly more efficiently, save fuel and lower costs for the airlines.
Would any ML or BN ENR controllers like to make a comment?