Page:UK Traffic Signs Manual - Chapter 8 - Part 2- Traffic Safety Measures and Signs for Road Works and Temporary Situations) - Operations 2009.pdf/32

OPERATIONAL ISSUES When visibility of the signs and the works is seriously affected by the onset of adverse weather conditions, it may be appropriate to improve the advance warning by the addition of high intensity flashing warning lights on the approach to the site. These flashing warning lights may only be used where allowed under regulation 54.

If the conditions persist it may be advisable to cease work and to clear the site of all personnel in the interests of their safety. In exceptional cases, it may be better to clear the carriageway of all obstructions due to the works if this can be done safely. The initial decision in any of these eventualities is for those supervising the works and maintaining the traffic management, although the final decision is for the police and/or client and will depend on all the prevailing circumstances, including the nature of the works, the volume of traffic and the characteristics of the weather conditions.

Access to and exit from the works area require signing both for the purpose of directing works traffic and to alert other road users of the likelihood of works vehicles making unexpected manoeuvres. Care needs to be taken to ensure that these signs do not obstruct sight lines and neither obstruct the view of, nor are obstructed by other signs.

For works vehicles to gain access to a site, cones and barriers may have to be removed. Unless these cones and barriers are replaced immediately, other vehicles may follow the works vehicles into the site and in built-up areas visually impaired pedestrians may stray on to the site.

Traffic entering or leaving works accesses should behave in the same manner as traffic entering or leaving any side road. The introduction of a new access may require the provision of "side road ahead" signs to diagram 506.1 on the public road and the signs may carry an additional plate to diagram 7301, with the legend "WORKS ACCESS". Right turns into sites on single carriageway roads should be avoided unless traffic control is used. The responsibility rests with drivers of emerging vehicles to manoeuvre safely.

Where construction traffic, especially heavy earth-moving equipment, regularly crosses an existing public road, the junction should be signed as for crossroads and a "HEAVY PLANT CROSSING" plate variant to diagram 511 should be provided below a "crossroads ahead" sign to diagram 504.1. The normal road works signing, including portable traffic signal control, will also be required on the public road. For more information on haul routes see Part 1: Design, Section D3.23.

Only prescribed or authorised signs may be used on public roads. Unauthorised signs, such as "Caution Lorries Turning", must not be used and would be considered an obstruction of the highway.

The "NO WORKS TRAFFIC" sign variant to diagram 7301 may be displayed in order to prevent the use of selected routes by works traffic seeking to gain access to a nearby site.

The "WORKS TRAFFIC" sign to diagrams 7303 to 7306 may be used to direct traffic to a works access. The contract number of the access may be added to this sign in order to identify a particular access but the sign will then need to be authorised by the appropriate Secretary of State.

To improve the conspicuity of the access point to approaching works vehicles, close-spaced cones to Detail B may be used over a distance of approximately 20 m before and after the access point.

When works are in progress on motorways and other dual carriageway roads, works vehicles shall not cross from one carriageway to the other by means of the emergency crossings or the central reservation. Any existing emergency crossing points within the length of the road works should be closed. For routine maintenance, vehicles should reach the other carriageway by means of the nearest junction. 30