AS 1742.4 pdf download.Manual of uniform traffic control devices
This Standard specifies the traffic control devices to be used for the regulatory control of traffic speed. The Standard does not cover temporary speed limits or the use of advisory speed signs. NOTE Speed matters excluded from this Standard are covered in the following references: (a) Temporary speed limits at works on roads — AS 1742.3. (b) Determination of advisory speeds and the use of supplementary plates — AS 1742.2. (c) Unsigned limits applied by existing legislation to classes of vehicle or driver, e.g. National Heavy Vehicle Regulator and jurisdiction regulations and guidelines.
1.2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document: NOTE Documents for informative purposes are listed in the Bibliography. AS 1348, Roads and traffic engineering — Glossary of terms AS 1742.2, Manual of uniform traffic control devices, Part 2: Traffic control devices for general use AS 1743, Road signs—Specifications AS 4049.5, Paints and related materials — Pavement marking materials, Part 5: Performance assessment of pavement markings AS 5156, Electronic speed limit signs
1.3 Terms and definitions
For the purpose of this Standard the definitions in AS 1348 and those below apply. 1.3.1 expressway type road divided highway for through traffic with full or partial control of access and generally with grade separation at intersections Note 1 to entry: The term includes expressways, freeways, tollways and motorways. 1.3.2 local area area containing only local and collector roads which is bounded by arterial and sub-arterial roads or features such as rivers, railway lines or the limit of urban development 1.3.3 local street road or street that serves primarily to provide access within a locality 1.3.4 may indicates the existence of an option 1.3.5 shall indicates a statement is mandatory 1.3.6 should indicates a recommendation 1.3.7 speed limit maximum speed at which a vehicle is legally permitted to travel on a particular section of road 1.3.8 speed zone length of road or a network of roads (an area) to which a single speed limit applies and which is signposted 1.3.9 traffic control device any sign, signal, pavement marking or other installation placed or erected by a public authority or official body having the necessary jurisdiction, for the purpose of regulating, warning or guiding road users 1.3.10 traffic route road or street that serves primarily to enable travel between localities Note 1 to entry: Typically, arterial, sub-arterial and major collector roads. 1.3.11 85th percentile speed V 85 speed, in kilometres per hour, at or below which 85 % of all vehicles are observed to travel under free- flowing conditions past a nominated point Note 1 to entry: A guide to the determination of 85th percentile speed is given in AS 1742.2.
2.1.1 Objective of speed management The objective of speed management is to contribute to road safety, mobility and amenity on public roads by providing a system of speed limits that are compatible with the speed environment. Speed limits should be set so as to encourage, as far as practicable, a uniform speed of travel and hence reduce the potential for conflicts due to speed differentials between vehicles. Excessive variation among vehicle speeds can indicate either an inappropriately set speed limit or that drivers’ perception of the speed environment is open to confusion. The second of these causes may require corrective action other than reassessment of the speed limit.
2.1.2 General principles
22.214.171.124 Determining speed limits The following recommendations and requirements apply when determining speed limits: (a) Speed limits shall be capable of being practically and equitably enforced by use of speed zones of adequate length, by limiting speed limit changes, and by clarity and frequency of signposting. (b) Where the speed limit exceeds the maximum safe speed of travel due to an isolated geometric deficiency or hazard, advisory speed signs displayed in conjunction with the relevant warning signs in accordance with AS 1742.2 shall be used to advise drivers of the desired speed. (c) Speed limit signs on unsealed roads have traditionally displayed the default urban or default rural limit. Jurisdiction supplements may provide guidance if other speed limits are to be permitted within that jurisdiction. (d) All signposted speed limits shall be in multiples of 10 km/h (except for a variation in South Australia that allows 25 km/h in school zones and road work sites).