Page:UK Traffic Signs Manual - Chapter 4 - Warning Signs. 2013.pdf/55



Diagram 557.1 is used to warn of the presence of a road hump or a series of humps. It must be accompanied by one of the plates shown. The plates must not be used alone. However, no signs are required to warn of humps in a 20 mph zone signed with traffic signs to diagram 674 (Highways (Road Humps) Regulations 1999). Road hump signs will usually benefit from the relaxation from the direct lighting requirement described in para 1.37.

Figure 13-1 illustrates the range of signing that might be used where road humps are installed on adjacent roads within an area. Signs are needed at each entrance to the area, other than at short culs-de-sac with no humps and fewer than about 100 dwellings. If the humps are spaced more than 150 metres apart, each individual hump should be signed. Similar signing should be used where humps are installed on one road only.

Individual circumstances will determine whether signs for road humps should be provided on both sides of the road. Where a gateway is to be used as a speed-reducing feature in advance of humps, it is recommended that signs should be erected on both sides of the carriageway and incorporated into the gateway. Further advice on siting can be found in Appendix A.

Where several adjoining roads have humps, the distance on the sign plates should relate to the humps on the road on which the sign is erected. Separate signing for adjoining roads should not be necessary, provided the first hump in the adjoining road, whether it is the major or the minor one, is within 40 metres of the junction of the two roads.

As humps may be installed only on roads with speed control features, a 50 mm x-height is sufficient for the supplementary plate, 557.2. Diagrams 557.3 and 557.4 when incorporating an arrow indicate the presence of humps on side roads, and may themselves be used on roads where speeds are higher. A wider range of x-heights is therefore prescribed for these signs (see Annex B for details).

Signing of a humped Zebra or signalled crossing in a series of road humps will generally be necessary only if the spacing between it and adjacent humps is greater than 100 metres (see also para 9.13 for details of sign plates). 54