Page:UK Traffic Signs Manual - Chapter 8 - Part 1 (Traffic Safety Measures and Signs for Road). Designs 2009.pdf/69

DESIGN CRITERIA

VMS provide a higher visual impact to passing motorists than static sign plates and are less likely to be missed. The use of temporary VMS (typically trailer-mounted) may be considered as an addition to fixed signs. Any messages displayed on these signs must comply with regulations 53(1) and 58, and Schedule 15 to the Regulations. A specification for portable variable message signs is given in document TR 2518 which is available at www.tssp|ansregistry.org.

VMS can be particularly useful at the following locations:
 * near advance road work warning signs where queues are likely to form;
 * in the lane change zone (i.e. within 800yds to 200yds) of a lane closure in place of wicket signs indicating a closed lane (7202), and
 * as additional support to keep left (or keep right) arrow signs at point of lane closure.

On wider carriageways there is greater chance of near side signs being obscured to off side traffic by vehicles in the near side lanes. Certain types of temporary VMS are high mounted and this type of sign is particularly useful when a sign is required on the verge and there is no suitable location for an off side sign.

When required, temporary traffic regulation orders should be used to ban turning movements and enforce lane and carriageway restrictions such as contra-flow working, carriageway closures and speed and vehicle restrictions which are needed to guide and control traffic safely past the works.

Where temporary traffic restrictions are required, these should be established for each site and made by means of a temporary order under Section 14 of the or Article 50 of the Road Traffic Regulation (NI) Order 1997. Specific reference must be made in the order to the hard shoulder where it is being used as a running lane to ensure that it is covered by the temporary order, because in general it is not part of the carriageway. Separate orders are recommended for a lane closure and for hard shoulder running. The Highway Authority should be consulted to ascertain whether or not the above actions in respect of hard shoulders apply.

The design programme for such works should make provision for the time necessary to obtain the appropriate temporary traffic regulation orders. Where there is insufficient time to obtain temporary traffic regulation orders under normal procurement procedures, consideration should be given to obtaining a traffic order under emergency notice procedures (Section 14(2) of the ), or in collaboration with the police under their powers.

The designer may need to give consideration to the following issues:
 * speed-related issues (Section D3.7);
 * no overtaking orders,
 * signing and enforcement,
 * use of the hard shoulder as a running lane,
 * contra-flow running, 68