Plan DZB6: Lane-change zone for a single lane closure on a dual carriageway road for which the national speed limit applies
Four pairs of advance lane closure signs are required:
- wicket signs indicating the closed lane (7202) with distance panel "800 yards" (7208) on the near side and the off side, placed 800m in advance of the works lead taper. These signs, with appropriate distance plates (600 yards, 400 yards and 200 yards), are placed at 600 m, 400 m and 200m in advance of the works lead taper, and
- on dual carriageway roads of five lanes when the works require closure of the near side lane, and on dual carriageway roads of six lanes when the closure of two near side lanes is required, subject to certain flow limits (see paragraph [[#D6.13.11|D6.13.11), the wicket signs indicating the closed lane (7202) on the off side of the carriageway may be omitted.
Where a temporary mandatory speed limit is in place, one pair of temporary speed limit signs is required, followed by repeater signs:
- the temporary speed limit sign (670), which will generally be 50mph, is to be placed on the near side and on the central reservation 50m in advance of the first sign indicating lane closures or restrictions (e.g. signs to diagram 7201, 7202, 7201.1), and
- for a temporary speed limit of 50mph the distance between successive repeater signs on the same side of the carriageway should not exceed 700 m, with a maximum of 450m between consecutive repeater signs on alternate sides of the carriageway. For temporary mandatory speed limits of 40mph or less, see Table 3.4, Note 1.
For entry taper details, including relaxations, see Plan DZB3.
Signing to Detail A is located on the hard shoulder opposite the "keep left/right" sign (610) at the start of the taper and at the end of the taper.
For works for which relaxations apply, the size of signs to diagram 7202 in the left-hand side of the carriageway should be as given in Tables A11 and #tableA1.2|A1.2 (Appendix 1) but the signs on the central reservation may be reduced to 1350mm. The x-height on the supplementary plate to diagram 7208 should be reduced proportionally.
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