Speed limits in Australia range from 10 kilometres per hour shared zones to 110 kilometres per hour. In the Northern Territory four highways have 130 kilometres per hour zones, speed limit signage is in km/h since metrication on 1 July 1974. All speed limits are multiples of 10 km/h – the last digit in all speed signs is zero, Australian states and territories use two default speed limits. These apply automatically in the absence of posted speed restriction signage, school zones are variable speed zones, with a 40 kilometres per hour limit applying during gazetted school terms and at specific times of the day when children are expected to be present. In South Australia, the limit is 25 kilometres per hour, a minority of school zones have flashing lights to indicate when the lower speed limit applies. Common speed zones above the limits are, Many sub-arterial roads are zoned 60 kilometres per hour. Major connector roads and smaller highways are zoned 60 kilometres per hour,70 kilometres per hour,80 kilometres per hour or 90 kilometres per hour, some highways and freeways are zoned 110 kilometres per hour. Most of the Stuart, Arnhem, Barkly and Victoria highways in the Northern Territory are zoned 130 kilometres per hour and it contains the word END and a number in a black circle beneath this, representing the ceasing speed-limit. It is typically used where, according to AS1742 and it is intended therefore to invoke particular caution. This sign is used as a replacement for the slash-through speed derestriction signs common in Europe. Speed limits are enforced in almost all areas of the country except for areas of the Northern Territory. This was updated in 2006 to require that the speed indicated shall not be less than the speed of the vehicle. Detection measures used are radar, LIDAR, fixed and mobile speed cameras, Vascar, pacing, despite introduction of model national road rules by the states in 1999, Western Australia and the Northern Territory retain different default speed limits. The table below indicates the speed limits along with typical school zone limits. In the external territories, and in special cases, the speed limits may differ significantly from those found across the rest of the nation. Historically, Australia operated a simple speed limit system of urban and rural default limits, with the onset of metrication in 1974, speed limits and speed advisories were converted into kilometres per hour, rounded to the nearest 10 km/h, leading to small discrepancies in speed limits. The urban default, which prior to the 1930s was 30 miles per hour, applied to any built up area, usually defined by the presence of street lighting. This limit was increased to 35 miles per hour over the next 30 years by each of the states and territories
Image: 50km speedlimit
Most urban freeways in Australia have speed limits of 80, 90, 100 or 110 km/h. This example is of the EastLink tolled motorway in Melbourne.
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