Warning Sign/Double Bend

Pre-Worboys sign

Before the Worboys Report of 1964 the Double Bend sign conformed to the earlier design system with a Red Triangle at the top of the post above the rectangular plate with the symbol above 'Double Bend'. The symbol was similar to the one still in use today, in other words a black line depicting the road travelling through a capital 'N' shape. The symbol could be reversed, as it still is today, to depict which way the first bend went, so producing a back-to-front 'N' shape. Examples have also been seen where reflective studs mark out the N to make the sign more visible in the dark, as was the case with other pre-Worboys signs.

The same symbol was also rotated to become a 'Z' shape for use when the road was generally bendy ahead, rather than specifically being a double bend. In these cases, the text below was Bends for x mile(s), and in the example shown, both the road symbol and the '1' are highlighted with reflective studs.

Worboys Report sign

After the Worboys report, the double bends sign was re-designed to conform to the new design standards. This saw the symbol moved into the red triangle to make the sign more compact. Initially, both the "Z" and "N" versions were used with "Z" warning of a series of bends and the "N" symbol a double bend. However, the "Z" sign was phased out in 1975 and since then the 'N' or reverse 'N' are the only permitted signs.

The modern sign

The 'N' symbol became the standard from 1975. It is not, as some may believe, just the former 'Z' sign rotated, but a new symbol with the two vertical strokes extended, and the upward one terminating in a arrow. This is much closer in design to the original pre-Worboys sign as above. The warning triangle alone warns of a double bend, but accompanied by a supplementary plate detailing a distance which the hazard extends over ("for x yds/miles") warns of a series of bends over that distance. Both uses are often accompanied by the large red Reduce Speed Now sign.

Irish signs

Sign W 053R

Ireland has four signs:

• W 052L – two sharp corners in close proximity, with the first to the left
• W 052R – two sharp corners in close proximity, with the first to the right
• W 053L – a series of sharp bends, with the first to the left
• W 053R – a series of sharp bends, with the first to the right

"Corner" = inside radius of 20 m or less and change of direction of approximately 90°.
*Bend" = inside radius greater than 20 m but requiring drivers to reduce speed considerably.

All of these signs are to be used "sparingly, and only where drivers will experience difficulty in negotiating the corner or bend without slowing down".