AS 1742.4:2020 – Manual of uniform traffic control devices Part 4: Speed controls.
It Is recommended that signs provided as In Items (a)(l) and (b) be placed on both sides of the roadway.
3.1.6 Repeater signs
Repeater signs are used within a linear speed zone to confirm the speed limit applying within the zone. They are provided in accordance with the following requirements and recommendations:
(a) They may be provided just beyond the beginning of a zone where there is a speed reduction at the start of the zone and there Is evidence that the limit Is not being adequately observed.
(b) They may be provided elsewhere within the zone as a regular reminder of the speed limit.
(c) They shall be provided as in Item (b) where the speed limit is inconsistent with the speed environment.
(d) They should be provided just beyond important intersections for the benefit of drivers who have turned from another road, If the limit Is other than the default limit.
(e) They shall be provided where there are frequent changes to the speed limit and drivers require the additional confirmation of the limit that applies at any point.
(f) They are not generally used within a default urban or rural speed limit
(g) Where used, they shall be located and spaced as follows:
(I) Just beyond a change of speed limit (Item (a) above) — a single sign on the left side of the roadway not exceeding 500 m beyond the start of the limit.
(Ii) At locations Inconsistent with the speed environment (Items (c) and (e) above) — single signs on the left side of the roadway at a spacing of 0.8 km to 1.0 km.
NOTE It is nut expected that signs will be required for this purpose in speed zones above 90km/h.
(iii) As a general reminder of the speed limit (Item (b) above) — single signs on the left side of the roadway at a spacing no greater than approximately 4 mm (urban) or 10 mm (rural) of travel time at the speed limit.
(iv) Just beyond an intersection on the major road (Item (d) above) — a sign on both sides of the road up to 150 m (urban) or up to 400 m (rural) beyond the intersection.
(h) Except as below, the Speed Limit R41R. sign shall be used as the repeater sign In all cases. In low speed urban areas, generally where the speed limit is 60 km/h or less, Sign, R4-1A may be substituted ii it will be sufficiently conspicuous against the urban visual background. The sign R4.IC is required on expressways.
3.1.7 Typical applications of speed limit signs
Typical applications of speed limit signs to indicate both default urban/rural limits and speed zones are Illustrated in Figures 3.1(A) and 3.1(B).
A school zone shall have at Its start an assembly consisting ota Speed Limit (R44) sign with the SCHOOL ZONE (R4-8) sign and a Times of Operation (R9-1 series) sign mounted below or beside it. The times of operation shall indicate the days on which the operating times apply, e.g. SCHOOL I)AYS.
A supplementary plate with the legend WHEN CHILDREN PRESENT may be substituted for the times ol operation plate subject to jurisdictional regulations.
A pair of horizontally opposed alternately flashing yellow lights on a black target board may be used above the school zone assembly.
The layout of the three signs in the assembly may be varied, however it should be consistent within a jurisdiction. The signs may he assembled on a single signboard.
An electronic sign may take the place of part or all of the assembly.
The end of the zone shall be indicated by a Speed Limit (R4-1) sign showing the continuing speed limit beyond the school zone and may include the END SCHOOL ZONE (R4-9) sign mounted above or below it.