Perth is good for bike riders. There are bike lanes and shared paths around the river, in kings park, and along the cost, freeways and train lines which any type of bike can use - even ebikes! These paths easily accomadate 30+kph (not that you have to ride that fast on a road bike of course). Sensible riders will slow down for walkers and when passing slower riders. I'll assume the OP is sensible. Commuting hours can be hectic and fast and some group rides have a reputation for being carelessly fast. And there's the occasional idiot. But the majority of riders that use these paths are sensible, at least this is my experience.