DUAL CARRIAGEWAY ROADS
Plan DZC8: Lead-in zone for a three-lane crossover with narrow lanes
Guidance on the design of the crossover is given in Section D6.5.
The principles for the crossover are:
- "lane restriction" signs (7201 with symbols 7281 and 7283 or 7283.1)with top panel "NARROW LANES" (7264) on the near side and off side 150m in advance of the start of the crossover;
- two "diversion of lanes onto other carriageway" signs (7210) located on either side of the carriageway at the start of the crossover;
- coning to Detail E is used on the near side;
- coning to Detail F is used on the off side;
- if a buffer zone is present the coning to Detail F on the off side is followed by cylinders and studs to Detail K, (it narrow lanes are not present then Detail H is used);
- one "keep left/right” sign (610) at the start of the crossover; if this is placed in a closed lane, as opposed to a normally non-trafficked area such as the verge, a footway or a hard shoulder, then a "lane closed" barrier (7105) with a high intensity warning light should be added;
- one "lane closed" barrier (7105) with a high intensity warning light and a "keep left/right” sign (610) at the end of the crossover;
- one "lane closed" barrier (7105) with a high intensity warning light and a "keep left/right” sign (610) atthe end of each lane crossed; in this context the central reservation is equivalent to either one or two lanes crossed, depending on its width;
- white lining or temporary studs to Detail J used as road marking between lanes; and
- a temporary mandatory speed limit will be in place; signs to diagram 670 should be continued from the lane-change zone; for the spacing of speed limit repeater signs, see Table 3.4, Note 1.
No relaxations apply.
Where the hard shoulder is not used for a works entry, and works access signs are not in place, an additional Detail A should be placed at the start of the coning blocking the hard shoulder.
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