4.2 Defining Path Alignment
A constructed path alignment may not be immediately obvious to the user if the path material merges well with the surrounding ground, or the path passes through a rough or eroded area. To prevent inadvertent movement off the managed path, further definition will be required in the form of sensitive path edge restoration and landscaping.
Good path management entails encouraging walkers to stay on the managed path. Defining path alignment is one of two techniques used, the other is covered in containing path use.
The purpose is to:
- reduce use to a single line and prevent it spreading across a wider area
- minimise the impact of the path in the upland landscape
- revegetate and stabilise weak or poorly vegetated path edges
As well as being an essential element of pathwork, it can be a minimal impact technique to define a path line without the use of surfacing materials. This is suitable on stable stony or eroded ground, where path use has spread over a wide area. The aim is to provide a more comfortable walking surface, within a clearly defined width.
Bill of Quantities (example)
Define one path line. Remove any loose large stone and obstructive boulders or turf islands to the path margins. Set in boulders and transplant turfs as informal path edges to define the path line and width.
Path definition requires great care. An aim of pathwork is to minimise its impact in the landscape and path definition will conflict with this if it is not sensitively undertaken. Defined path sides should merge naturally into adjoining ground. The methods used must be appropriate to the character of the path, its surface and the surrounding landscape.
- turfing the path edges
- shaping or restoring banking at path edges
- placement of stabilising stone
- movement of loose stones, boulders and turf islands
The types of materials available are usually quite limited, and include:
- Boulders and stone
These materials and the general principles for their use are detailed in materials and use.
A single pathline should be defined wherever problems are encountered with walkers following a variety of lines across a wide area of rough ground. This involves the careful "sorting" of the natural, or eroded, surface material.
All rough loose stones and boulders are removed from the preferred path alignment, unless they provide good, and solid footholds. Small stone is scattered in the alternative lines. Larger stone and boulders are then set into the ground to define an informal path edge. Any islands of turf remaining are carefully transplanted either at the path edge or in the alternative lines to provide a natural appearance, appropriate to the surrounding area.
The alternative path lines may need additional blocking (see containing path use).
Turfing of the aggregate path edge may have been undertaken as part of the construction, particularly where the path tray sides were unstable, or geotextile used. Additional definition, with turfs and boulders if appropriate, may be needed at changes in alignment, and to help vary the path width. Turfing may also be required to slightly raise the path edges and prevent the aggregate surface from spreading or eroding with use. The use of turfs will soften the edges and encourage vegetation to grow into the aggregate.
Turfs should be laid right up to the path edge, maintaining a variable path width. Care should be taken to avoid creating straight lines. Incorporating small boulders or large stones can help to give a natural look to regular turfing, as long as they are randomly placed, and not in a uniform line along the path edge.
Pitched paths are often constructed through wide rough and eroded areas. The placement of boulders and turf, particularly at changes in width and alignment will help to define the edges.
The path surface should be lower than the adjoining ground and the turfing angled down to form a bank that is not suitable for walking on. The turf should be butted tightly into the pitched stone, to encourage it to grow over and soften the edges.
Where a traversing path is benched into the slope the uphill bank may become under-cut by path use, weathering, or sheep sheltering. This can lead to overhanging turf that is liable to collapse onto the path. A path that has eroded to form a stable mineral surface can also leave over-hangs, on both sides.
In these cases it is necessary to reshape and stabilise the path sides. This can be done by rebuilding the eroded bank with boulders, and turfs. Alternatively, if no material is available, the turf may be carefully lifted, the soil underneath reshaped down to the path edge, with the overhanging turf transplanted over it. In both methods the banking should be angled back, so that undermining is less likely to reoccur.
Wherever drains extend outside the path width the path edge should be defined with large turfs or stone. This helps to soften the appearance of a stone drain and stabilise the path edge where it joins the drain construction. Care is needed in placing the turf to avoid channelling path use into the drain rather than onto the path.
Key points to watch:
- make sure that boulders or stones are secure and will not move onto the path line
- ensure that edge definition channels walkers onto and not off the path
- avoid regular and even placement of turf and boulders - position randomly
The following maintenance may be required:
- replace any dead, worn or displaced turfs
- re-set, or replace any loose or dislodged boulders
- create natural path edges - merge them with adjoining ground
- use a mix of turf, stone and boulders appropriate to the surrounding landscape
HEALTH AND SAFETY HAZARDS
- be aware of any steep drops or slopes when working on path edges
- stand back before completing alignment definition - make sure the path line is appropriate and other measures are in place to keep walkers on the path