Page:UK Traffic Signs Manual - Chapter 4 - Warning Signs. 2013.pdf/16

 occurring within the distance shown on the plate should not be signed individually. However, they may be highlighted individually using diagram 515 (see paras 3.13 to 3.19).

Use of the adverse camber plate to diagram 513.1 to supplement a bend warning sign may be appropriate for signing a sharp bend where no superelevation has been applied. The sign may be used in other circumstances where loss of control accidents are attributed to insufficient superelevation, eg a right hand bend on a steep downhill gradient, or when circulating a roundabout. However, over-use will devalue the sign and it should be used only where the problem is likely to be severe.

Drivers should expect to encounter adverse or insufficient camber on roundabouts. While approach alignment should ideally ensure that vehicles, particularly HGVs, enter the roundabout at a safe speed, this is not always possible. Where there is a problem of large vehicles overturning on the entry to, or circulatory carriageway of, a roundabout, the non-prescribed sign to diagram NP 423 (see figure 3-1) can be considered. The lower panel can be omitted or varied to diagram 513.2. Note that this sign requires special authorisation (see para ). Although this sign includes a pictorial representation of an overturning lorry, it lacks the recognisable red triangle. It should therefore be used only to supplement standard warning signs.

The advisory speed sign to diagram 513.2 "Maximum speed advised"is prescribed for use only in combination with the "Loose chippings" sign to diagram 7009 (see para 12.4) or the bend warning signs to diagrams 512, 512.1, 512.2 or 513. The sign should be used sparingly, as in general it should be for drivers to judge what speed to adopt. It is not easy to determine a standard safe speed to negotiate a bend; factors which influence this include radius of curvature, camber/superelevation, road surface condition and type of vehicle. The sign may be used where the road layout is such that a driver might be misled, eg at an exit from a high-speed road where significant slowing is required before negotiating a sharp bend. It may also be used on high-speed roads where the horizontal design radius cannot 15