Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/51

DESIGN CRITERIA NOTE: Appropriate advance warning signs should be placed on the cross arms of the junction.

Guidance on the conduct of traffic surveys is given in TA 11 "Traffic surveys by roadside interview" (DMRB 5.1 .4) and that document should be read in conjunction with this section.

Generally, it is not possible for the traffic management layouts at survey sites to conform fully with the road works traffic management plans shown in Sections D5 and D6. This is because of the nature of the survey work and the limited road space available at selected sites. The survey plans provided are based on previous survey traffic management arrangements where a police officer was in attendance.

Typical layouts and signing for interview sites are given in Plans SV1 to SV3. The plans indicate principles and minimum requirements. Some local discretion in their application may be necessary for optimum safety and operational efficiency, depending on the traffic flow, speeds, type of road and information required on the nature of the survey. Surveys may need to be carried out in conditions where it is not possible or appropriate for traffic to be funnelled into a single lane of slow-moving traffic, or stationary traffic at signals, and TA 11 provides guidance on alternative survey layouts. All survey sites present an obstruction on the highway and it is essential that they are subject to a site specific risk assessment.

Where the space available for a survey site is limited, Table 3.6 identifies the spacing of signs and minimum length of lead tapers for single and dual carriageway roads. 50