Road signs help to regulate, warn and guide
road users for the safe and efficient movement of traffic.
Transport is responsible for the installation and maintenance of
- traffic signs on arterial roads
- standard Clearway signs
- regulatory signs on Council maintained side roads which
relate to Transport SA roads.
Parking restriction signs are, however, determined and maintained
The type and placement of road signs is very
important and is carefully considered. For signs to be effective they need to
make meaning clear at a glance
allow adequate response time.
Signs and other traffic devices lose effectiveness if used
unnecessarily or too frequently, so their use is restricted to the minimum consistent
with safety requirements.
Application Form for Tourism and Services Road Signs
Categories of road signs
There are 4 categories of road signs in Australia
Regulatory signs instruct road users of their legal obligations eg speed limits,
prohibited or permitted movements at intersections, and parking controls.
Most regulatory signs are rectangular with a black
legend on a white background.
- stop signs (octagonal)
- give way and roundabout signs (triangular)
- speed restriction signs (symbol enclosed in a red circle)
- no right hand turn signs (red slash to indicate the prohibition
of a movement)
- prohibitive parking signs (red legend on a white background)
- permitted parking signs (green legend on a white background)
Warning signs indicate hazards which may not be obvious to the approaching
Warning signs are a diamond shape with a black legend or symbol on
a yellow background to indicate caution.
Warning signs include
- advisory speed signs (to safely negotiate bends)
- advance warning of traffic control devices (such as traffic lights)
- road conditions (eg slippery when wet).
Guide signs inform motorists of
- direction and / or distance to destinations
- points of interest and roadside facilities
Route numbering signs in the metropolitan area
Transport SA has introduced a route numbering system to South
The alpha-numeric system consistent with interstate
practice complements the existing metropolitan route systems and will
guide both local and visiting road users through unfamiliar areas by the most
- expanding residential development to the north and south means that local
road users are no longer familiar with the whole of metropolitan Adelaide
and it is becoming increasingly difficult to find an easy and safe route to,
and through, other areas
- changing nature of work and lifestyles has created a diversity of travel
patterns and trip purposes
- increasing number of tourists and country visitors have reported that there
is a lack of directional assistance to newcomers.
The new route numbering is gradually replacing the National Highways
route system in the metropolitan area. National highways are shown by the alfa-numeric
number and the word National on the route number shield
by the side of the road.
The route numbering marker signs are rectangular with
- letter and number in gold on a green background
- M for freeway or expressway
- A for a main route
- B for a secondary route.
Traffic signs, especially at major intersections, will gradually be modified
or replaced to show the road user the
- new route numbers.
- name of the road being travelled.
- name of the major crossroads being approached.
- destinations along each leg of an intersection.
Transport SA has signposted designated routes covering the
- metropolitan area
- selected country areas including main tourism locations of Victor Harbor
and the Barossa Valley.
Future phases will involve rural areas and outer metropolitan
Route numbers give road users a short ‘burst’ of information that
is easier to see and remember than changing road names, and
forms part of the overall system of sign information.
A road user unfamiliar with areas of Adelaide will find it easier to arrive
at their destination by using a combination of
- route numbers
- improved signing.
A sales representative based in Salisbury but needing to call on a potential
customer in the Marion Shopping Centre would currently be advised to follow
- leave Salisbury via the Salisbury Highway to cross the Port Wakefield Road
and join the South Road-Salisbury Connector to pick up South Road. Follow
South Road to the junction of Sturt Road. Turn right on to Sturt Road and
follow until you reach the Marion Shopping Centre.
In future, the directions could be as simple as
- take the A13 from Salisbury, then turn right at Sturt Road.
Truck noise advisory signs
You may have noticed signs asking truck drivers to Avoid Using Noisy
Exhaust Brakes around the metropolitan and country areas.
These advisory signs are
- currently being trialed at specific locations in the urban area
- located at strategic sites in Adelaide and the State borders
- specifically target long distance heavy vehicle operators.
Transport SA has responded to community concern about excessive
truck noise in residential areas. Noisy engine brakes are a common complaint
and yet it is one of the easiest problems to fix.
Next to the USA, Australia relies on private road transport more than any other
country in the world.
Use of engine brakes has become a normal driving habit but
is unnecessary in most situations and especially in flat residential areas.
Transport SA is asking freight transport industry associations, owners
and operators to cooperate in changing driver’s habits.
Ongoing education of the transport and freight industries
is also a key platform for the success of reduced heavy vehicle noise in urban
A supporting information brochure has
been distributed to operators to
- raise awareness of the signs
- increase appreciation of the need to reform driving behaviour.
With advances in technology it is expected that future auxiliary braking
systems will be much quieter.
Over time noise emissions should reduce through
- improvements to the vehicle fleet
- changes in driver behaviour.