The current state government has finally, after five years (permission was refused by the previous government), granted permission to the City of Melbourne to introduce 40km/h speed limits in the CBD. If you ride in the CBD, you will notice the speed limit progressively being rolled out. For details of the roll-out see the City of Melbourne website.
This is a positive first step. The difference between 50km/h and 40km/h speeds, in terms of the likelihood of fatality or injury for bike riders and pedestrians hit by a car, is significant. Those that drive in the CBD, especially at night, will know that it was a myth that 50km/h was only an aspirational speed and was never actually reached. Even on weekdays, cars can reach 50km/h in parts of the CBD.
The evidence-based speed limit for areas where cars, bikes and pedestrians mix is 30km/h, as we have written about before. This speed will need to be achieved both through speed limits and traffic calming. This is the direction governments should be headed in:
And from the Monash University Accident Research Centre:
See also the UK campaign "Twenty's Plenty" (20mph = 30km/h).