In response to resident requests for speed reduction without further use of physical devices, a trial 40 km/h limit was established in a residential area of Unley, South Australia, supervised by a broadly-based Working Party. Speed cameras were used to enforce the limit, initially at low-levels judged to be sustainable in the long-term, and later at much higher levels. Median traffic speeds fell by 5 km/h following the launch of the trial, and reduced very little after that despite high levels of enforcement towards the end of the trial one year later. Residents' concern over traffic issues did not decrease. Although ratings of how noisy, how much traffic, and traffic speeds on the resident's own street changed little during the trial, 29% thought noise had reduced and 39% thought speeds had reduced. Although over half the residents had seen enforcement in action, few had been caught speeding or knew someone who had. There was very strong support for the limit and its continuation. (A)
Abstract