60 km/h speed limit sign
Speed limits in Australia range from 10 kilometres per hour (6.2 mph) shared zones to 110 kilometres per hour (68 mph). In the Northern Territory three highways have 130 kilometres per hour (81 mph) zones and two sections of the Stuart Highway are unlimited. Speed limit signage is in km/h since metrication on 1 July 1974. All speed limits (with the sole exception of the South Australian school and roadworks zones which are signposted at 25 km/h) are multiples of 10 km/h – the last digit in all speed signs is zero.
Common limitsSizes of speed limit signs are governed by Australian Standard 1742.4 released in 2009 130 km/h speed limits are found on the Stuart, Barkly, Victoria and Arnhem Highways 35 km/h speed advisory sign above a keep left sign
Australian states and territories use two "default" speed limits. These apply automatically in the absence of 'posted' speed restriction signage. The two default speed limits are:
- within built-up areas, 50 kilometres per hour (31 mph), except for the Northern Territory which remains at 60 kilometres per hour (37 mph)
- outside built-up areas, 100 kilometres per hour (62 mph); two exceptions are Western Australia and the Northern Territory at 110 kilometres per hour (68 mph)
Common speed zones below the default built up area 50 km/h limit are:
- Shared zones (signposted areas where pedestrians and motorised traffic share the same space) are 10 kilometres per hour (6.2 mph).
- School zones are variable speed zones, with a 40 kilometres per hour (25 mph) limit applying during gazetted school terms (which may include pupil-free days) and at specific times of the day when children are expected to be present. In South Australia, the limit is 25 kilometres per hour (16 mph). A minority of school zones have flashing lights to indicate when the lower speed limit applies.
- 40 km/h zones. A number of local governments have implemented lower speed limits, typically 40 km/h, in certain areas, such as shopping precincts, or even in whole suburbs such as Balmain and Rozelle in Sydney.
Common speed zones above the default limits are:
- Many sub-arterial roads are zoned 60 kilometres per hour (37 mph).
- Major connector roads and smaller highways are zoned 60 kilometres per hour (37 mph), 70 kilometres per hour (43 mph), 80 kilometres per hour (50 mph) or 90 kilometres per hour (56 mph).
- Some highways and freeways are zoned 110 kilometres per hour (68 mph).
- Most of the Stuart, Arnhem, Barkly and Victoria highways in the Northern Territory are zoned 130 kilometres per hour (81 mph).
- A 200 km stretch of the Stuart between Alice Springs and Barrow Creek in the Northern Territory is zoned with no speed limit from February 2014.