WS2+1

Signs indicating the end of the overtaking lane

Wide Single 2+1 or WS2+1 is a modern standard of single carriageway road which consists of three traffic lanes, two in one direction and one in the other direction.

The design is similar to the older S2+1 standard but differs in several ways. Most notably the double white line separating the opposing flows is 1 metre wide, solid on both sides with hatching and red infill, meaning traffic is not permitted to enter the opposing direction's lanes so overtaking can only take place in the direction with two lanes.

Also, there is special signage designed to indicate the road layout and, in particular, to convey clearly to drivers where the overtaking lane merges.

Standards

Overtaking lane changeover

The standard is defined by TD 70/08 of volume 6 of the Design Manual for Road and Bridges, issued in 2008.

The type of layout was first used on trunk roads in Scotland, notably the A9 and A68 in the early 2000s, although these pre-dated the formally laid out standard and slightly differ for what is now used.

Usage

A different style of signing was used when the layout was first developed

After being developed there, continued implementation of the design has been found mostly in Scotland, with Transport Scotland using it for upgrades of various trunk routes, including the A76, A96, A876 and further use on the A9.

Links

DMRB: TD 70/08