the driver's handbook

Obstruction
Blocking an intersection
You must not enter or attempt to cross an intersection if the
intersection or road you wish to drive into is blocked by other vehicles.
Driving too slowly
You must not drive so slowly that you obstruct the vehicle or vehicles
following you. For example, driving at 20 km/h without a good reason
where a speed limit of 80 km/h applies.
Emergency vehicles
It is an offence to obstruct a police or emergency vehicle with the
warning siren sounding or displaying red and/or blue flashing lights.
You must not move into the path of, and must move out of the path of
and Give Way to ensure that the emergency vehicle is provided with
a clear and uninterrupted passage. You are allowed to disobey other
road rules in order to move out of the way, but only if it is safe to do so.
Keeping clear of trams
You must not drive into the path of a tram travelling on tram tracks if
there is a continuous yellow line on the left side of and parallel to the
track. If a tram approaches, you must not obstruct the tram and must
move on as soon as you can do so safely.
Parking
You must not park or stop your vehicle in a way that could be likely to
obstruct other road users or be a danger to other road users.
Blocking or obstructing other road users is not
only discourteous but potentially dangerous.
The Driver’s Handbook 79