It's not comparable. A right turn on red is allowed at traffic lights in the US, unless signposted otherwise. A left turn on red is disallowed at traffic lights in Australia, unless signposted otherwise.

I think the latter (default disallowed) is safer, because the sign permitting turn on red states that the turn is only permitted after stopping. On the other hand, drivers in the US blow through their right turns on red, usually not stopping, and with impunity.