Resurfacing and surface dressing
|Take a look at our 'Large-scale project works' page for our 2021 resurfacing and surface dressing programmes.|
We spend around £9 million each year on resurfacing and surface dressing the county’s roads, ranging from unclassified rural roads to town centre roads to main ‘A’ roads.
The information and video on this page will tell you all you need to know about the resurfacing and surface dressing work that we carry out on Shropshire’s roads.
Why do we resurface the roads?
Resurfacing is a vital part of highways maintenance. It improves the long-term condition of roads, helps to prevent problems in the future, and means we don’t have to spend as much time on smaller repairs, e.g. filling in potholes.
Did you know? The highways maintenance service is delivered mainly through five local (divisional) offices, two of which are within the North area (in Hodnet and Whittington). The Hodnet office delivers the highway maintenance service for the Whitchurch and Prees area. Larger countywide programmes are managed by a central team.
How do we decide which roads to resurface?
All adopted roads are subject to safety inspections and the frequency of these inspections is determined by the category of the road. All defects that are recorded or reported are categorised and prioritised for repair as per guidelines set out the Code of Good Practice for Highway maintenance 2005.
We gather and analyse information from:
- regular inspections – these can be weekly up to annually, depending on how busy the road is and how important it is locally and economically
- annual surveys using specialist equipment – these include a mixture of mechanical and visual surveys which provide detailed information about the condition of roads.
- reports from councillors, parish councils and community groups – we work closely with parish and district councils to listen to their thoughts on what is important locally.
- reports from residents – anyone can report a problem on the road.
This data is used to assess the condition of the entire network around 5150 km of road.
We use the data to find out the most cost effective type of repair and make a yearly resurfacing plan. To achieve value for money, we prioritise roads that are likely to need costly repairs in the future.
Once the prioritisation process has taken place, funding is allocated to the specified works to be carried out.
When do we resurface the roads?
We plan to carry out as much resurfacing as possible during the warmer months. Surface dressing is carried out between mid-April and late August as it relies on warm dry weather.
A road closure is needed in most cases to help ensure the safety of road users and those carrying out the works. To minimise disruption to highway users these works can on occasion be carried out overnight and on weekends.
School holidays and local events are considered when work is planned and programmed.
How do we resurface the roads?
Roads are maintained through either resurfacing or through surface dressing. We select the right method at the right time to get best value for money.
1. Surfacing and reconstruction works
These works traditionally involve overlaying or inlaying large areas of carriageway and, where necessary, carrying out deeper reconstruction on isolated areas where significant structural failure is evident.
Coring investigation work is undertaken beforehand to fully assess the work required. This is to ascertain if tar is present within construction layers so that preventative measures can be carried out.
Overlaying involves treating the existing surface with a tack coat on to which a new surface course is applied.
Inlaying involves planing and milling of the existing surface, followed by the application of tack coat and new surface course. With both there is the need to adjust the height and level of all ironwork along the affected length.
We generally resurface roads using Asphalt Concrete (bitumen macadam), Hot Rolled Asphalt or another product chosen to meet local site conditions.
How long will resurfaced roads last?
Resurfacing with hot bitumen will last for approximately 10 to 20 years dependent on the volumes of traffic using the road. Surfacing with micro-asphalt can be expected to last between 5 and 10 years.
2. Surface dressing
Surface dressing is a simple and highly cost-effective method of repairing the road surface, which can prevent much more expensive work being needed later. It allows us to maintain a high quality road network on a finite budget.
The process involves spraying the road surface with a coating of hot liquid bitumen, known as a binder. The coating is then covered with clean crushed stone chippings, which are rolled into the bitumen to form a water-resistant, protective layer, which improves skid resistance.
It’s a mobile operation that allows us to reduce the time on site, minimising disruption to road users.
This type of work can only be undertaken in the spring and summer months, when the weather is warm and dry, as the bitumen will not stick to the road in cold or wet conditions.
Why we use surface dressing
Surface dressing offers many advantages:
- It seals the road surface which prevents water getting in to the underlying road structure.
- It slows the deterioration of the road surface and underlying road structure.
- It restores skid resistance to the road surface.
- It helps to reduce spray caused by vehicles travelling on wet road surfaces.
- The rapid speed of the process means that disruption to road users, local businesses and emergency services is minimised.
- It lasts up to 10 years, maximising the cost-effectiveness of limited highway maintenance funds.
Highway maintenance treatment types
Surface Dressing -- Covering the carriageway with stone chips embedded in bitumen. This type of repair provides more grip and protects it from water and air damage. It is generally used on busy rural or urban roads and lasts up to 10 years. We fix faults and potholes and then coat the road with an adhesive layer followed by stone chips. This is embedded with the help of vehicles and we return three times over the following week to remove excess stones.
Rejuvopatch -- Covering the carriageway with a veneer of cold laid surfacing material. To seal the surface, improve skidding resistance and restore visual/ride quality, mainly in urban areas.
Haunching -- Excavating the edge of the carriageway to about 500mm depth and replacing the materials with a new road structure. To strengthen the road edge where it has failed, often prior to surface dressing or resurfacing.
Resurfacing/Overlay -- Covering the carriageway with a minimum thickness of 40mm of dense hot laid surfacing material. To replace a failed surface which is not suitable for Micro surfacing or surface dressing. Resurfacing restores ride quality, skidding resistance and can reduce noise.
Reconstruction -- Excavating the carriageway to about 500mm depth and replacing the materials with a new road structure. To replace a failed road structure.
Recycling -- In-depth recycling, remixing the existing carriageway to 500mm+ and mixing with either cement or bitumen. To reuse existing materials from the failed road to form a new construction which can then be resurfaced.