[David Hodgson]

It's an ADR and not a local rule. It's not specifically to do with side pipes but more so addressing the issue of all types of vehicles gassing out pedestrians/shoppers on the side walk etc. The rule also sets an angle toward the ground that the outlet must meet.

An engineer here in the ACT got one through with pipes exiting both sides on the grounds there was physically no room to take them further back.

original DRB's from QLD and Snake Pit Sydney had both pipes exiting together on the right and a fake on the left to meet this requirement.