Variable lane controls are used to direct traffic on or off certain lanes when events, incidents or closures occur, or where there is a need to optimise efficient movement of traffic flow, such as tidal flows to cater for demands of peak traffic volumes. Not all lanes need to be designated for traffic flow, for example, a three-lane road could, at times, comprise one lane for each direction of travel with the middle lane not designated for any traffic flow.
Clause 7.13 (1) of the TCD rule states that:
(1) The use of a lane may be controlled by means of variable lane control signs that are installed above the lane and that display:
(a) a red diagonal cross, indicating that the lane is not available to road users that are travelling in the direction facing the sign; or
(b)a green downward-facing arrow, indicating that the lane may be used by road users that are travelling in the direction facing the sign; or
(c) a yellow diagonal arrow facing to the bottom left or right corner of the sign, indicating that road users must, as soon as practicable, move to the adjacent lane to the left or right; or
(d) if 7.13(7) applies, a blank display indicating to road users that the lane is available for use.
(2) The symbols stated in clause 7.13(1) must comply with the relevant requirements in Schedule 1 [of the TCD Rule; specifications can be found in the sign specifications].
Sign specifications(3) If a lane has road users travelling in opposite directions at different times, only the following combinations of symbols may be displayed:
(a) a green downward-facing arrow displayed for one direction with a red diagonal cross displayed for the opposite direction;
(b) a yellow diagonal arrow displayed for one direction with a red diagonal cross displayed for the opposite direction;
(c) a red diagonal cross displayed in both directions.
(4) If the use of a lane is changed so as to reverse the direction in which road users must travel, the symbols displayed must have the following sequence:
(a) a green downward-facing arrow displayed for one direction with a red diagonal cross displayed for the opposite direction, followed by either:
(b) a diagonal yellow arrow displayed for one direction with a red diagonal cross displayed for the opposite direction followed by a red diagonal cross displayed for both directions; or(i) a red diagonal cross displayed in both directions;
(c) a red diagonal cross displayed for one direction with a green downward-facing arrow displayed for the opposite direction, in the reverse order from that specified in (a).
(d) A red diagonal cross specified in 7.13(4)(a)(i) or (ii) that is displayed concurrently for both directions must operate for a period that allows safe clearance of traffic from the lane.
(i) If the use of a lane is changed to exclude road users travelling in one direction for a period, after which the lane reopens for road users travelling in the same direction, the symbols displayed must comply with the sequence in 7.13(4)(a)(i) or (ii), followed by a green downward-facing arrow displayed for the one direction with a red diagonal cross displayed for the opposite direction.
(ii) If lanes used for road users that are travelling in opposite directions are separated by physical barriers:
the signs above each lane may be a green downward-facing arrow, a yellow diagonal arrow, a diagonal red cross or a blank display facing road users travelling in that lane; and
symbols do not have to be displayed for road users travelling in the opposite direction.
(5) If 7.13(7) applies, the symbols displayed must comply with either of the following sequences:
(a) a green downward-facing arrow or a blank display, followed by a diagonal yellow arrow, followed by either:
(b) a diagonal red cross followed by a green downward-facing arrow; or
(i) a green downward-facing arrow; or
(c) a blank display followed by a diagonal yellow arrow, followed by either:
(d) a red diagonal cross, followed by a blank display; or
(i) a blank display.
The overhead signs used to direct traffic on or off certain lanes are illustrated in Table 10‑2; these are generally lit. More detailed specifications on the variable lane control signs are contained in the TCD manual sign specifications.
Table 10‑2: Variable lane control signs
|
Sign code |
Example |
Description/use |
|---|---|---|
|
R4-4
|
|
The R4-4 sign is used to indicate that the lane may be used by road users that are travelling in the direction facing the sign. This sign is generally lit. |
|
R4-5 (L)
|
|
The R4-5 (L) sign is used to indicate that road users must, as soon as practicable, move to the adjacent lane to the left. This sign is generally lit. |
|
R4-5 (R)
|
|
The R4-5 (R) sign is used to indicate that road users must, as soon as practicable, move to the adjacent lane to the right. This sign is generally lit. |
|
R4-6
|
|
The R4-6 sign is used to indicate that the lane is not available to road users that are travelling in the direction facing the sign. This sign is generally lit. |
