Guidance Bulletin 34
Is It Wide Enough? When is a road closure the only option?
When works require the restriction of the usable width to a live carriageway there are several key elements which Officials should be considered when assessing the appropriate method of traffic control. When the works including the coned safety zones restricts the usable carriageway width to less than the permitted absolute minimum widths of 3.0m (Normal traffic including buses and HGV) or 2.5m (Cars and light vehicles only), the works must not progress until a road closure has been applied for and communication has been made with the Highway Authority.
The sideways clearance
This is the width between the working space and moving traffic. The sideways clearance is measured horizontally between the edge of the working space and the edge of the carriageway in use by vehicles. It will vary with the speed limit (0.5m on roads 40mph or less, 1.2m on roads 50mph or more). This space forms a safety zone, this zone is provided to protect you from traffic and the traffic from you. You must not enter the safety zone in the normal course of work. Materials and equipment must not be placed in the zone. You will need to enter the zone only to set up, maintain or remove the cones and other road signs.
If you cannot fit your works and a safety zone in without restricting the carriageway width to below the absolute minimums, you must consult your supervisor and the Highway Authority immediately as a road closure may be the only safe option.
IF YOU ARE IN ANY DOUBT, CONTACT YOUR SUPERVISOR FOR FURTHER ADVICE
DO HIGHWAYS THE RIGHTWAYS