Ernie Clark. Hilperton Division, Wiltshire Council.

I never realised that there were so many variations...

The planned repair to Trowbridge Road is a 'Surfacing Site' but the existing material isn't suitable for re-use. This is why the road wasn't repaired last year.

The types of treatment most frequently used are:

• Major Maintenance Schemes.

Schemes are carried out which involve substantial carriageway reconstruction and surfacing, often including kerb works, drainage improvements and changes to carriageway cross falls, alterations to the road alignment, and improvements to signing and lining to improve safety.

• Minor Improvement Schemes.

Smaller schemes are carried out to alter bends or junctions to improve safety over short sections of road, usually with changes to drainage, kerbs and lining and signing. Sites are identified on the basis of the accident record or in response to concerns about existing conditions.

• Surfacing Sites.

There is a programme of work to resurface roads with hot rolled asphalt and bituminous materials. This usually involves the removal of the existing deteriorated road surface, repair of any structural failure, and resurfacing of the whole road.

• Carriageway Repair Sites.

Reconstruction and resurfacing of short lengths of a road to repair localised damage and extend the life of the road are carried out at particular locations. This takes place when there are sections in poor condition, but the whole road is not yet in need of surfacing.

• Recycling,

On roads where there is substantial structural failure, the whole road construction can be broken out, mixed with new material and relaid. The material in the existing road needs to be suitable for re-use, which is not always the case, and careful consideration has to be given identifying sites.

• Surface Dressing.

This is the traditional ‘tar and chip’ which has been used for many years on rural roads. Localised damage and defects are repaired before resurfacing the whole road. It is a cheap treatment which protects the underlying construction and provides good skid resistance. The process is mainly suitable for rural locations.

• Micro Asphalt.

This is a proprietary product which is more expensive than surface dressing, but produces a robust ‘black–top’ surface which is particularly suitable for urban or built up areas. It has proved to be very durable when used in the right locations.

The choice of scheme or treatment type depends on the situation, and the timing of the work can be critical in ensuring the durability of the finished works.