Single Carriageway Ahead Permanent UK Road Sign 

- Post Mountable with 2 fixing rails

- Class 2 R2/RA2 Reflective

- Available in 450mm, 600mm, 750mm, 900mm Tri

This sign is used to warn road users of a road layout change from a duel carriageway to and single carriageway with two-was traffic. Often placed directly after a duel carriageway ends sign. Diagram 521 has no variations. 

Specification: 

Material: R2/RA2 reflective overlay on aluminium composite backing

Fixing Method: 2 fixing rails for post mounting

Reflectivity: Class 2 R2/RA2

As per the UK Highways Traffic Sign Manual Chapter 4 - Warning Signs page: 29 The following advice is given:

5.1.1.  The signs to diagrams 520 (S2‑2‑15, see Figure 5-1) and 521 (S2‑2‑16, see Figure 5-2) indicate the resumption of two-way traffic on a single carriageway road after a length of dual carriageway and, in the case of diagram 521, after a one‑way road. The sign to diagram 522 indicates a two‑way road crossing ahead (S2‑2‑17, see Figure 5-3 and 5.2.2).