Why can you drive faster on some roads than others? Who is responsible for setting the speed limits on our roads and can the speed limits be changed?
NRMA’s Motoring Advice team get asked many of questions, so we got to the bottom of how speed limits are set in New South Wales (NSW).
Why do we have speed limits?
The setting of safe speed limits is an integral part of protecting road users' safety on NSW roads. According to Transport for NSW, almost 40% of all road related fatal crashes and 16% of injury crashes in NSW have speed as a factor.
Who sets the speed limits in NSW?
The Road Transport (Safety and Traffic Management) Act 1999 empowers the Roads and Traffic Authority (RTA) (now, Transport for NSW) ) to set the speed limits on NSW roads through traffic regulations. Transport for NSW determines the speed limits for all roads and road users based on a standardised set of guidelines and national agreements which aim to regulate the maximum speed of travel under good road and travel conditions.
What are the standardised guidelines?
Speed limits are set in accordance with the NSW Speed Zoning Guidelines. These guidelines are developed and applied by road safety experts and traffic engineers from Transport for NSW. The guidelines themselves, are based on international and evidence-based best practice in speed management, Australian Standards, Austroads Guides, state legislation, government policies and plans. They’re kept up-to-date through incorporating the latest advances in research and technology, as well as integrating road safety objectives and traffic management initiatives.
How are speed limits set?
The key principle in setting speed limits for a length of road is that the established speed limit should reflect the road safety risk to road users, while maintaining the ability of people to easily get to their destination. A number of key factors are considered in establishing the speed limit including; crash profile, width of lanes, road function, road use, roadside development, road characteristics, road alignment/profile, traffic mix, crash history and the presence of vulnerable road users, such as pedestrians, motorcyclists and bicycle riders.
Other factors include the number, type and frequency of driveways and intersections (traffic lights/roundabouts etc) which indicate potential conflict points. These conflict points are considered because they allow vehicles to turn across traffic where there is a chance of a ‘t-bone’ type of crash occurring.