26 April 2018

As the weather starts to improve, Northamptonshire County Council has started the spring phase of its extensive highways repair programme.

Every year there is a planned programme of works which involved various treatment methods, running alongside the reactive maintenance that addresses issues highlighted by routine inspections and reports via Street Doctor.

Roads everywhere are vulnerable in wintery weather as heavy rain, frost and snow all act to make surfaces more susceptible to deterioration.

This has been one of the most severe winters in recent years with three major snow events and well over 100 gritting runs carried out.

Cllr Ian Morris, county council cabinet member for transport, highways and environment, said:


“A combination of winter weather and increased heavy usage causes damage to roads and footways not just here but throughout Britain.

“With less and less money available to us for repairs we need to make a little go a long way and use innovation to make the public pound stretch further.

“We recognise that our roads are not acceptable but we don’t have the funds locally to make a significant impact on this. We’ve stated before that it would take about £100million of investment to bring the network up to a good standard.

“Part of what we do is making representations to central government for more money to bring about road improvements but we also have to be mindful that we’re competing with other authorities for the funds and that government has its own financial pressures.

“However we are very hopeful that our significant efforts to use innovation to find efficiencies will be recognised.”

The next phase of the Northamptonshire Highways repair programme is to carry out the road patching that is required before preventative maintenance can be done. This is seeing heavily potholed areas of the highway patched in preparation for the extensive ‘micro asphalt and surface dressing’ programme.

Micro Asphalt

Micro asphalt is an economical way of resurfacing roads which are starting to show the first signs of wear and tear. This is used when the structure of the road is good but the very top surface is beginning to wear and needs sealing to stop water getting in, preventing major deterioration.

Surface dressing

Surface dressing involves hot tar being sprayed on to the road surface and overlaid by chippings which are rolled on to the surface. When the tar cools it sets and holds the chippings to the surface of the road.

Surface dressing is recognised as a cost-effective way of preserving and extending the life of highways. This prevents the disintegration of the road surface and seals the surface of the road against ingress of water to protect its structure from damage.

The process creates what are commonly known as loose chippings and as a result traffic is slowed to 20mph to reduce the danger of partially embedded chippings flicking up in the first few days. Loose chippings are swept away within 24 hours of the initial dressing, and again within three days.

A heavy roller is used after initial treatment and the surface is usually fully embedded after around a week, due to the action of traffic moving across it.

The carriageway is safe to drive on following application of the chippings, provided speeds remain below 20mph. For safety, people are advised to drive slowly, keeping their distance, and to avoid turning or braking sharply. Motorists should also avoid overtaking.

Both micro asphalt and surface dressing are dependent on fine weather and, as such, the programme of works is liable to change.


The county council is always looking at new ways of repairing roads in a cost effective and safe way. New innovations are trialled throughout the year to see if they can be added to existing methods of repair. This year Northamptonshire Highways is using a patch planer – a JCB with a planer on the front to repair road surface defects.  A trial of the machine carried out last year showed that the machine was very productive and mobile, being able to travel easily between sites.

The patch planer allows an area-based approach where an identified road will have all the potholes patched rather than those that only meet the intervention levels, meaning communities will see a much wider areas of repairs in their neighbourhood.

This is a cost effective and controlled way of patching that offers a semi-permanent repair that has been proven to last longer than normal patching.

Information for residents

Where micro asphalt and surface dressing is scheduled in residential areas, people will receive a letter through their door notifying them of when the work will take place and asking them to move their vehicles off roads and paths. Advisory signs will also be placed in the streets.

Vehicles, whose presence is preventing or hindering the works taking place, may be relocated to an adjacent street. This will be carried out by an approved contractor and vehicles will be moved within the vicinity, with signs located on the street providing information.

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