Signing, Lighting and Guarding of Roadworks
The three duties
Under NRSWA s.65 and the Code of Practice, works must be signed so drivers get warning and guidance early enough to react, guarded so vehicles and pedestrians cannot enter the works or fall into it, and lit so the layout is visible at night and in poor light.
Signing works from the outside in: advance warning signs on every approach, then the taper of cones into the closure, then the works area, then repeaters or additional signing on long or complex sites. The distance from the first sign to the works increases with the speed limit - around 45 m on a 30 mph street and progressively further as speeds rise - and the sign must be sited where it is visible for that distance, not around a bend or hidden behind a parked vehicle. Signs face oncoming traffic, are stable, at the correct height and are removed or covered when the works are finished or suspended.
Guarding uses Chapter 8 barriers and cones, not cones alone, for excavations and deep openings. Lighting uses lamps that mark the extent of the works; they must be lit whenever required and checked during the shift.
Traps
Common errors in questions: putting the first sign after a junction or crest; signing only one direction of a two-way street; leaving cones or signs out overnight after reinstatement; using cones to guard an open trench; forgetting pedestrian provisions (a signed walkway, ideally at least a metre wide, with ramps and a crossing point); and using stop/go boards or portable signals on roads too fast for them.
Worked example: a 30 mph residential street needs a trench across the footway. Typical answer: advance warning sign roughly 45 m back on each approach, pedestrian walkway of at least 1 m with a ramped crossing, barriers around the excavation, lamps for night.