Page:UK Traffic Signs Manual - Chapter 8 - Part 2- Traffic Safety Measures and Signs for Road Works and Temporary Situations) - Operations 2009.pdf/146

MOBILE CARRIAGEWAY CLOSURE TECHNIQUES

When one of the options where the slip road is closed at its downstream end is used for a closure during the hours of darkness, it is important that the area in the vicinity of the actual closure is well illuminated. On unlit slip roads this will mean the use of temporary lighting.

At junctions where the movement of traffic is controlled by traffic signals, it may be appropriate to use the signal controller to manually set the signals to all-red on the arms approaching the particular slip road that is to be closed temporarily. If this all-red period is likely to be prolonged, say, in excess of four minutes, then additional warning signs advising of this should be considered.

If the slip road is to be closed at its downstream end, i.e. the end nearer the main carriageway (Plans MCC2 and MCC3), if it is possible that the traffic flow on the slip road may cause vehicles to back up and cause congestion at the junction then additional signing will be required on the approach roads to the junction.

When the slip road is closed at its entry (Plan MCC4), a suitable diversion route should be signed. One option, if appropriate, will be to direct traffic up the opposing carriageway to join the affected carriageway at the previous junction. 144