Speed Management Research
Managing the speed vehicles travel on our roads is one of the most important factors in ensuring safety for all road users.
This briefing broadly explains how speed limits are set, why speed cameras are used, their effect, community attitudes to speed cameras, community education and “fixing” the roads.
Speeding is a significant contributor to road trauma and was a contributing factor in 25 per cent of fatal crashes in 2017. One highly effective way to reduce the incidence of speeding is through enforcement.
Fixed and mobile safety cameras operate in South Australia to discourage speeding and red light running behaviour. The belief you will get caught and fined is usually sufficient to deter people from speeding.
Recent evidence supports that this is the case for a majority of South Australians, with most of the driving population never receiving a fine or speeding infringement notice.
Summary and extracts of research data
Evidence-based research consistently demonstrates that safety cameras have a positive effect in improving driver behaviour.
a) Speed cameras for the prevention of road traffic injuries and deaths. Do speed cameras reduce road traffic crashes, injuries and deaths? The Cochrane Library.
The Cochrane Library (ISSN 1465-1858) is a collection of six databases that contain different types of high-quality, independent evidence to inform healthcare decision-making, and a seventh database that provides information about Cochrane groups.
To evaluate the effectiveness of speed cameras, the authors examined all eligible studies, that is, studies that met pre-set standard criteria. We analysed the effect of speed cameras on speeding, road traffic crashes, injuries and deaths by comparing what was happening in road areas before the introduction of speed cameras and after their introduction, and also by analysing what was happening in comparable road areas where no speed cameras were introduced during the study period.
The authors accepted a total of 35 studies for review which met the pre-set criteria. All studies reporting speed outcomes reported a reduction in average speeds post intervention with speed cameras. Speed was also reported as either reductions in the percentage of speeding vehicles (drivers), as percentage speeding reductions over various speed limits, or as reductions in percentages of top end speeders.
A reduction in the proportion of speeding vehicles (drivers) over the accepted posted speed limit, ranged from 8% to 70% with most countries reporting reductions in the 10 to 35% range.
Twenty eight studies measured the effect on crashes. All 28 studies found a lower number of crashes in the speed camera areas after implementation of the program. In the vicinity of camera
sites, the reductions ranged from 8% to 49% for all crashes, with reductions for most studies in the 14% to 25% range.
For injury crashes the decrease ranged between 8% and 50% and for crashes resulting in fatalities or serious injuries the reductions were in the range of 11% to 44%. Effects over wider areas showed reductions for all crashes ranging from 9% to 35%, with most studies reporting reductions in the 11% to to 27% range.
For crashes resulting in death or serious injury, reductions ranged from 17% to 58%, with most studies reporting this result in the 30% to 40% reduction range. The studies of longer duration showed that these positive trends were either maintained or improved with time.
The consistency of reported positive reductions in speed and crash results across all studies show that speed cameras are a worthwhile intervention for reducing the number of road traffic injuries and deaths.
b) Evaluation of the Fixed Digital Speed Camera Program in NSW by ARRB Group Project Team for Roads & Traffic Authority, NSW
Selection of sites for fixed digital speed camera use in New South Wales
A set of criteria was developed by the RTA, in consultation with NSW Police and NRMA Motoring and Services, for selection of fixed digital speed camera sites (the camera length). The criteria assess crash rates and vehicle speeds over a length of road of between one and 3.3 kilometres (the camera length or black length) where the camera is intended to reduce speeding and crashes.
The crash analysis involves a review of the rates of crashes occurring over a length of road relative to the traffic volume, the severity of the crashes and the travel speed of the prevailing traffic. The crashes are compared with predetermined rates for three road type categories: rural, urban and freeway/motorway.
This evaluation has shown that after the installation of 28 fixed digital speed cameras across various sites in New South Wales, significant reductions were achieved in vehicle speeds, speeding rates and crashes. Statistical analysis of speed and crash data has shown that significant reductions in speed parameters and crash numbers are attributable to the presence of the fixed digital speed cameras.