Page:UK Traffic Signs Manual - Chapter 8 - Part 2- Traffic Safety Measures and Signs for Road Works and Temporary Situations) - Operations 2009.pdf/159

MOBILE CARRIAGEWAY CLOSURE TECHNIQUES

The closure vehicles move towards the working area travelling at either 20 mph or 30 mph. When they reach the working area (Plan MCC1c), work on the carriageway must have ceased and the carriageway have been cleared for the passage of traffic.

In the case when the highway within the works area remains obstructed outside the closure window, an emergency situation has been created and it may be necessary to stop the convoy. Emergency situations must be reported to the police and the Highway Authority immediately.

If the closure vehicles have to stop, the length of the queue behind them may increase rapidly. The advance warning vehicles should stop and maintain their position and available matrix and VMS signs should be set to give the necessary warning to traffic approaching the end of the queue.

If there are no lane closures, removal shall be the reverse of the procedure detailed in Section O11.12 used to establish the closure except that each closure vehicle will accelerate to normal road speed in turn and merge in front of the adjacent closure vehicle, i.e. the lane 3 vehicle will merge in front of the lane 2 vehicle.

When there is an off side lane reduction at the start of the works area, the following procedure should be adopted to remove the closure:
 * 800 m from the start of the cone taper, the closure vehicle in the lane to be closed should switch from the red cross sign to the flashing "keep left" light arrow sign (Plan MCC7, Phase 1);
 * at 200 m from the start of the cone taper, this vehicle (Vehicle 3 in Plan MCC7) accelerates then merges in front of the closure vehicle to its left (Vehicle 2) so that the vehicles behind have a clear view of the lane closure ahead and can react accordingly (Plan MCC7, Phase 2); if possible, an impact protection vehicle displaying a "keep left" light arrow sign should be positioned within the works area to reinforce the presence of the lane closure; and
 * the hard shoulder vehicle rejoins the main carriageway in front of Vehicle 1 approximately 200 m before hard shoulder signing commences.

Note that for a near side closure, this operation is reversed with Vehicle 1 merging etc.

The closure vehicles increase their speed up to the limit applicable at the works site and travel through the works area maintaining the closure (Plan MCC7, Phase 3).

When the closure vehicles have passed the working area, they resume normal speed and move to the left-hand lane of the carriageway to allow traffic to pass (Plan MCC7, Phase 4). The operation is then complete and the closure vehicles may return to their rendezvous point. 157