Speed Limits on Tasmanian Roads
What is a speed limit?
A speed limit is the maximum speed that you are allowed to travel along a road.
The speed limit is not a target speed, and the speed that the driver chooses to travel needs to be adjusted to suit the conditions (such as weather and traffic volumes).
Who sets speed limits in Tasmania?
The legal authority for setting speed limits on all roads in Tasmania is the Commissioner for Transport. Typically, the Commissioner will make a decision after considering an application and recommendation from the relevant road manager.
How are speed limits set?
Speed limits need to provide a reasonable balance between traffic flow and local infrastructure. Setting realistic speed limits is important to ensure road user's obey the speed limit. For example, it has been shown that setting low speed limits for higher speed limit environments can result in less compliance.
Key factors include*:
- roadside development, particularly the number of accesses along the road which is a proxy for the likelihood of conflict between through traffic and turning traffic,
- road function and traffic volume,
- road width and alignment, and crash history.
*Technical guidance on setting speed limits is provided in the Australian Standard AS1742, Part 4.
Are speed limits on gravel roads different?
On the 1st of February 2014, a new maximum speed limit of 80 km/h was applied to all gravel roads in Tasmania unless otherwise signposted.
Drivers need to be more vigilant on gravel roads as they are more susceptible to changing conditions than sealed roads. The appropriate speed on gravel roads may be considerably less than the default limit of 80 km/h which applies when conditions are good.
I sometimes see speed limit signs on road work sites when there doesn't seem to be any work occurring. What's happening there?
Speed limits sometimes remain in place after road works appear to have been completed. Generally they remain in place because certain road conditions make it unsafe to raise the speed limit. This might include things such as wet tar, loose gravel, uneven surfaces and other safety issues.
At other times, poor weather conditions may prevent the completion of road works for a long period of time and so the lower speed limit remains in place until the work can be finished. Speed limits on works sites are mandatory, meaning by law you must obey the speed limit and can be penalised if you do not.
What are variable speed limit systems?
These are systems that use electronic signs to change the speed limit to match the road conditions and situation. Changes might be triggered by a crash, an obstacle on the road, a queue of vehicles during peak times, or weather such as rain, ice or wind.
A Variable Speed Limit system can be seen operating on the Tasman Highway from Liverpool Street Hobart to the Cambridge Interchange, including the Tasman Bridge.
Variable electronic school speed signs operate across Tasmania. Operating times are determined by each school community and therefore differ from school to school.
What is the difference between the yellow / black speed signs and the white signs with the red circle?
Speed signs that are white with a red circle enclosing the back speed limit show the upper most limit which you are able to travel. These are mandatory speed limit signs.
Speed signs that are yellow with black writing are known as "speed advisory signs". They are a guide to the safe speed you should use for the location to which the sign applies.
Speed limits signs that are erected for road works, lane closures or special events are also white with a red circle enclosing the back speed limit. Although temporary, they are also mandatory.
Tasmania Police has the power to enforce mandatory speed limits on our roads and to penalise non-compliance.
If you need further information on the setting and management of speed limits on Tasmanian roads please contact us at firstname.lastname@example.org.