Annual Road Maintenance Programme

The programme features the annual planned works which are funded from the capital investment budget and derived from a prioritisation process of works requirements.

In addition to the locations listed in the programme, the Road Maintenance Partnership also undertake routine and reactive works funded against the revenue budget. These additional works are typically defect repair works of a smaller scale to the projects funded under the capital budget. The routine and reactive works are identified and addressed continuously throughout the year and as such are not included in the annual programme.

The selection of optimum treatment type is determined by a number of influencing factors in accordance with asset management principles. Factors which determine the proposed treatment type include but are not limited to; the existing construction of the asset, deterioration extent and cause of failure, traffic loadings and strategic hierarchy of the road / footway, residual asset life assessment and pavement investigation / testing reports.

This form of treatment involves the removal (usually undertaken by milling / planing) of the road or footway surface course, which is the upper most layer of construction material, typically 40mm deep in roads and 20 to 30mm deep in footways. The excavated area is then reinstated with a new surface course material. A number of alternate surfacing materials are used by the partnership with the material choice being selected based on suitability and value for money criteria.

The term 'inlay' refers to the same process of resurfacing roads. The treatment title of inlay is often used instead of resurfacing where a greater depth of material is renewed than only the upper surface course layer. With bituminous or rigid layers of a road pavement typically being a depth of 300mm, the inlay is usually undertaken to a depth of up to 200mm, thereafter reconstruction interventions are typically required.

Similar in process to resurfacing however the new material is applied directly upon the existing pavement surface. This form of treatment provides increased value for money and a lesser environmental impact to resurfacing, due to the lesser excavation requirements, however isn't appropriate in all circumstances.

The specification of this form of treatment requires the condition of the existing pavement material to be structurally adequate to receive an overlay layer. If the existing surface is deteriorated to the point where material may become lose under trafficking it is often required to remove the failed layers. In addition the overlaying of new material results in a surface level increase of the road or footway which, particularly in urban areas, may require adjustment to kerbs, utility apparatus, gullies and potentially accommodation works to adjoining property frontages. The cost associated with accommodating the surface level increase can often out weight the financial benefits derived from omitting the excavation (milling / planing) element of the activity.

Reconstruction of roads and footways consists of excavation of all pavement layers to the sub-grade formation level. The typical depth of excavation is 450mm and 230mm in carriageways and footways respectively. Following excavation the pavement is reconstructed in compacted layers of new or processed recycled material.

This form of treatment is predominantly proposed where the full pavement asset has failed with limited residual life remaining in the asset to allow extension through lesser depth treatment interventions.

This form of treatment consists of sealing the road or footway surface with a bitumen emulsion and applying aggregate chips to the surface. The treatment provides an improved surface condition with increased grip levels. Of equal importance the treatment seals the existing construction layers beneath, lessening the ingress of water to the lower pavement layers preventing damage occurring through frost heave and expansion of existing micro-cracking.

The depth of treatment is typically 12mm which is applied as a surface level increase. In advance of the works, proprietary repairs are completed in the form of pre-patching to address any structural defects in the asset prior to sealing. Ironwork (utility covers and gully frames) are also assessed and where required raised and/or renewed to complete the maintenance treatment and compliment the revised surface level profile.

These forms of treatment both involve the overlaying of existing road surfaces with a thin layer of bound material. These treatments are often referred to as 'micro-surfacing'.

The systems allows for improvements to ride quality by regulating profile irregularities such as minor rutting or level deferential resultant from track or localised repair reinstatements.

A significant benefit of this treatment type is the lower cost per square metre when compared to greater depth treatments such as resurfacing. Where applied as a preventative treatment method a greater financial return in the whole asset life cycle can be achieved over corrective treatment intervention following failure.

Similarly to the surface dressing treatment, ironwork is reset and/or renewed and pre-patching works completed to rectify any localised structural defects prior to surfacing.

This form of treatment consists of recycling of the upper bituminous pavement layers into new surfacing material. In the case of in-situ recycling, the process involves milling / planing the pavement surface to produce a bituminous aggregate which is then mixed on site with new binder material applied prior to compaction. The process of ex-situ recycling is similar however the excavated surface layers are taken to a production plant off site to be reprocessed into new material.

The renewed construction is then finished with a surface dressing to provide a finished traffic surface.

The process is principally proposed on roads of lesser traffic volume however is suitable for high traffic weight loading routes such as industrial estate roads.

The in-situ recycling system allows both environmental and value for money benefits to be derived and is a well established treatment technique in the UK.