Speed limits in Australia range from 5 km/h (3.1 mph) shared zones to 130 km/h (81 mph). 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. Speed limits are set by state and territory legislation albeit with co-ordination and discussion between governments.