Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/113

SINGLE CARRIAGEWAY ROADS It will generally be characteristic of minor roads that:
 * traffic flows are less than 400 vehicles per hour, of which less than 5% are heavy vehicles;
 * bus services are infrequent;
 * pedestrian flows are small, less than 100 per hour;
 * parking or limited waiting may be allowed on one or both sides of the road; and
 * cyclists will be present.

Any road that does not match these descriptions, but which is otherwise regarded as meriting the description, may be treated as such by agreement between the Highway Authority and the police.

For works carried out off the carriageway there will be no need for signs to warn vehicular traffic where the clearances are as given in paragraph D3.20.2. Where these conditions cannot be met, pedestrians will need to occupy part of the carriageway and safety measures similar to those necessary for works in the carriageway should be adopted; see, for example, Plan SC3 in Section D5.6.

For works on the carriageway with no parked vehicles:


 * where there are no parked vehicles in the vicinity of the works, and there is no works vehicle in attendance to afford protection, the following signs should be provided together with cones and pedestrian barriers as necessary:
 * "road works" signs to diagram 7001;
 * "keep left/right” signs to diagram 610;
 * "road narrows” signs to diagram 517; and
 * "traffic lane or carriageway closed to traffic" signs to diagram 7105.

The "road works" sign to diagram 7001 should normally be placed 45m in advance of the works, but this distance may have to be greater if the visibility of the sign is impaired by features of the road. However, in urban areas the sign may need to be placed closer where there are numerous side roads so that the sign does not become disassociated from the works. Sections D5.4 to D5.1O provide details of different methods of traffic control.

Permitted reduced signing for works on the carriageway with a works vehicle in attendance or parked vehicles present, refer to Part2: Operations, Section O3.19.

The main factors affecting the decision on the type of control which is appropriate are: 112
 * visibility through the works area;
 * length of the controlled area;
 * volume of traffic flow;