Page:UK Traffic Signs Manual - Chapter 8 - Part 2- Traffic Safety Measures and Signs for Road Works and Temporary Situations) - Operations 2009.pdf/127

 Should the technique be used on a road with at-grade junctions (e.g. signals, roundabouts etc.) then gaps between vehicles may need to be reduced in the proximity of these junctions. At this type of location, the speed of the traffic reduces, approaching that of the MLC, and there is therefore an increased risk of vehicles invading the closure, either from a side road or by cutting in. This is exacerbated if the larger gaps normally used when traffic is passing at higher speeds are maintained.

Where the closure of two lanes is being carried out, if the works allow a choice of closing lanes 1 and 2 or lanes 2 and 3 then the latter option should be chosen since it does not require slower-moving traffic to change lanes.

Where hard shoulders are less than 3.3 m wide, the supervisor should decide whether or not safety may be prejudiced by operating or working on a narrow hard shoulder. If safety is being prejudiced then the operation should not proceed.

The block vehicle should maintain station with the working vehicle in front of it, at all times. When there is a particular risk of other vehicles getting between the MLC vehicles, the distance given as 50-100 m in the plans should be kept as close to 50 m as possible. To minimise the risk of the block vehicle being shunted into the works area this distance should never be less than 50 m in normal operation.

Where there are three lanes and the working vehicle is operating in the centre lane, Plan MLC3, three block vehicles should be used. These are shown as B1, B2 and B3 on the plan. This arrangement minimises any possible risk of errant vehicles passing between the block vehicles and by extending the length of the taper allows smoother merging of approaching traffic.

When the near side and centre lane are closed then depending on the location of the workforce within the closure, consideration should be given to providing an additional block vehicle on the hard shoulder alongside vehicle B3.

Work on foot on the carriageway may be undertaken in association with this technique. Plan MLC4 illustrates the principles involved. In the example depicted, the working area is shown as extending forwards and into part of the middle lane. In this situation, the working area should be protected by vehicles front and rear, and the rear vehicle should itself be protected by a block vehicle as shown. A lateral clearance or safety zone of not less than 1.2 m should be provided between the working space and the carriageway remaining open to traffic.

Where appropriate, steps should be taken to ensure that the workforce does not stray into the safety zone, e.g. when a team member is acting as a lookout.

When work is being carried out on foot, depending on the type of works being undertaken, additional block vehicles may be needed to protect the working area from errant vehicles. Where an additional block vehicle is positioned within the area protected by the main block vehicles, e.g. alongside vehicle B1, its flashing lanterns should be switched off.

The arrangement may be adapted for other situations, e.g. work on lanes 2 and 3 may be carried out using a mirror image of the plan.

When working alongside a central reservation which is wide enough for an errant vehicle to pass between the central reservation safety barrier and the block vehicles, the block vehicles should be positioned to prevent this happening.

When work is undertaken on foot on a hard shoulder a lateral clearance or safety zone of not less than 1.2 m should be provided between the working space and the carriageway open to traffic; see Section O3.2. 125