Surfaces
From GPG
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A most important part of any path is its surface and a 'golden rule' is that the more natural it can seem to be, the better. Nature has wonderful healing powers, but if there is heavy use on a route and/or if ground conditions are less than perfect nature may need a little help. However, after draining, reinforcing or improvement work of any sort, the aim is always to get the path looking as 'natural' as possible.
If a new surface is required there are many factors to consider before you decide on a surface type :
- the extent and type of use along the path
- the inherent local conditions
- wetness
- acidity
- shade
- animal activity, etc.
The vernacular context, colours, and local textures also deserves consideration. In an area where natural stone outcrops it is good to use the local stone on your paths.
Somehow, natural materials always look best on a surface in a way that plastics, tarmac, concrete and smooth machined timber never (or extremely rarely) can. Do consider the chemistry of your materials also. Do not put limestone into acidic moorland areas, or use basic slag type of material in the countryside, for example. Stick to materials which are chemically neutral.
Remember too that the finished surface needs to be kind to the foot, hoof or wheel (as appropriate). Does every RoW officer know what size of aggregate NOT to use on bridleways because it will stick in a horse's shoe? (If not see the CSS bridleway report) Have you tried walking down a slope of smooth, wet, limestone slabs?
Surfaces need to be consolidated everywhere. A loose surface is anathema to most users. But consolidation is particularly important on slopes as a loose surface there will mean that it all gravitates to the bottom of the slope eventually. Even dry slopes need well anchored cross rails at intervals to prevent slippage, and water flowing down the slope always exacerbates the problem.
This brings us to one of the key aspects of any path - drainage. Paths with long downslope sections need to have the water shed from the surface at regular intervals if any surface is to be preserved. Unfortunately, it is all too common to see expensive repairs ruined three years later because the drainage was inadequate. Where water is a major factor on site, there is much to be said for sorting out the drainage in the autumn, leave it all winter to see that it is working well and has dried out the area, and then re-surface in spring (in time for the growing season).
This leads on to re-vegetation. If the original damage and/or the repair work itself left one with lots of bare areas, do try to encourage natural re-growth to improve the appearance.
Maintenance liability
The extent of the duty to maintain (HA80 s41) requires that PRoW should be kept in such a state as to be safe and fit for ordinary traffic which could reasonably be expected to use it. In practice, the decision as to what surface to provide, if any, will be the level of use and its legal status. There is no obligation to provide a metalled surface or similar on a byway to enable the public to use the route with vehicles.
Dual liability
Many PRoW are privately maintainable to a higher status. Where dual liability exists the Highway Authority is only responsible for maintenance to the public status. If, for example, a landowner has provided a sealed surface for vehicular use on a farm track that has public bridleway rights, the Highway Authority cannot be held responsible for maintenance beyond that required for reasonable bridleway use.
Surfacing Techniques
See :
Surfacing Bridleways
The legal definition of a bridleway is to be found in s328 of the Highways Act 1980. It is repeated exactly in s66 of the Wildlife & Countryside Act 1981 :
Bridleway means a highway over which the public have the following, but no other, rights of way, that is to say, a right of way on foot and a right of way on horseback and leading a horse, with or without a right to drive animals of any description along the highway.
The definition should be read in conjunction with s.30 of the Countryside Act 1968 which gives pedal cyclists a right to use bridleways providing they give way to pedestrians and people on horseback, but does not affect the maintenance liability of highway authorities or make them improve the surface for cyclists.
The Act makes it clear that the primary users of a bridleway are pedestrians and horse riders and that the surface does not have to be altered to accommodate cyclists. It has been argued that pedestrians and horse riders effectively enjoy a higher right demonstrated by the fact cyclists must give way to both horse riders and pedestrians, however this can be countered by comparing the use of a carriageway i.e. vehicles should give way to pedestrians.
The issue of maintenance comes down to the Highway Authority's basic duty to maintain highways to a standard commensurate with their ordinary use. If the majority of use is by horse riders, the surface should be suitable for them, and if by cyclists then an alternative surface may be required (although see note s30 (3) above). However, whatever surface is provided should not be detrimental to other legitimate users e.g. a surface should not be provided that improves things for cyclists but makes it worse for horse riders.
Surfacing bridleways requires attention to detail: the surface must be robust enough to withstand the pressure of hooves, but not too slippery, or with loose material and because bikes can use the routes the surface must be safe for them too. Many bridleways are tracks or lanes and have private vehicular rights, further complicating the requirements of the surface.
The appropriate surface for any bridleway will vary depending on terrain, level of use and nature of use - examples of surface types are given in the CSS Bridleways report. These include :
- Grading and re-seeding
- Crushed stone
- Geo-textiles
- Woven reinforcing fabrics
- Scalpings
- Recycled crushed concrete
The report also includes sections on :
- Bridleway Maintenance - Legal Definitions
- Bridleway User Rights
- Conflict Perception
- Multi-use Trails Code of Conduct
- Bridleway Surfacing: Issues and Solutions
- Construction Drawings:
- Options for bridleway construction
- Pot Holes Repairs in Existing Bridleways
- Typical Cross Section of Shared Use Trail
and case studies.
Development of the Pennine Bridleway National Trail has lead to the development of several innovative approaches to bridleway surfacing, including use of machine built paths top dressed with crushed stone & combination pitched and seeded surfaces.
Advice and specifications for all surfacing and other works are given in the Pennine Bridleway design guide. Authorities responsible for managing the Trail have copies, and a full version will soon be available on the National Trails website.
The issue of surfacing highways to ensure they are safe for equestrian users is addressed by the CSS and British Horse Society in their report on Horses and Highway surfacing. The working group surveyed highway authorities to determine the scale of the problem and to find out what solutions were currently used. The report concludes that where slipping is a problem a surface treatment may be necessary to increase friction. Key tips for success are:
- Avoid the use of limestone aggregates
- If laying any bitumen coated surfacing, eg asphalt concrete (formerly referred to as macadam or colloquially as tar macadam) it is prudent to apply grit to the surface as per the guidance document.
- Surface dressing with uncoated aggregate (other than limestone) can be good but care must be taken to ensure that the aggregate does not strip or over-embed in use as this can lead to exposure of a bitumen film that may pose a slip risk.
Arten Gill - Yorkshire Dales National Park
The surface of the track down Arten Gill had washed away over many years leaving gullies up to 2m deep. Contractors were brought in to design and build a solution which would withstand the huge volumes of water currently on the track, and be suitable for horses, cyclists and withstand the private vehicular use of local landowners.
The finished surface included sections of stone pitching, crushed stone and grassed strips. Huge drains were installed under the track, and stone pitched fords built to take water across where necessary.
Many routes in urban areas or those carrying heavy traffic have traditionally been surfaced with asphalt to provide a sealed multi-user surface. In recent years, there has been debate over the use of asphalt as a surfacing for public rights of way. Asphalt surfaces are durable and smooth but the material can be too hard for comfortable horse riding or running. Softer surfacings, such as grass or sand, provide 'give' but these can impede some users and maintenance costs are higher. A surface that meets the needs of both horse riders and other users might be achievable using post-consumer tyre rubber.
CSS report on horses & highways :
In response to an increase in the number reported incidents of horses slipping on the highway surface the CSS & BHS have worked together to produce a guidance note.
The document gives guidance to local authorities & to horse riders. It found that in certain circumstances a surface "treatment" to increase friction is appropriate.
CSS guidance to Highway Authorities :
Areas to be treated must be determined locally. Complaints should be followed by an investigation.
Appropriate methods of treatment include:
- gritting during construction
- surface application or texturing post construction
BHS guidance to horse riders :
All horse owners using the highway in any context must exercise their duty of care as a road user together with their duty as horse owner.
Use of Rubber Crumb as Surface Material (WRAP project)
The Waste and Resources Action Programme (WRAP) is working in partnership to promote the use of used tyre rubber in UK rights of way through the new route initiative.
Already boasting a range of practical applications - including sea defences, landscaping and sports arenas - rubber from end-of-life tyres can be processed into grades of different particulate size which are then suitable for incorporation into pathways.
"Paths that incorporate used tyre rubber are more shock-absorbent than those constructed using standard materials, providing a more comfortable surface for users. This also increases the safety of paths by reducing the impact from falls and slips.
"The unique quality of rights of way made with used tyre rubber is that they can satisfy the comfort and practical requirements of walkers, joggers, cyclists, horse riders and other groups – making the material the ideal option for multi-user pathways. Because there are several potential methods of incorporation, rights of way constructed with used tyre rubber can be tailored to specific user groups."
Further information is available in WRAP documents:
- answers to frequently asked questions on the use of rubber crumb
- a technical report on the use of post–consumer tyre rubber in rights of way construction
- a technical case study of a Nottinghamshire bridleway.
and WRAP's website, which includes rubber suppliers and guidance.
System of Prioritisation for Works
Kent County Council uses a system for prioritising surfacing work very successfully. A similar format could be devised for many other capital projects. Using such a system enables officers to demonstrate a coherent approach to investment and to defend or justify priority order. This can be especially helpful when a demand from the public, particularly when escalated by a councillor or senior management, is for work that the officer does not consider significant against the list of priorities.
