Clyde Walkway (Smart Surface™)

Client: Paths for All

Location: Clyde Walkway, Lanarkshire

Timeframe: 2018



The Clyde Walkway is a 65km active travel route from Glasgow City Centre to the World Heritage Site of New Lanark. The route takes walkers and cyclists through many interesting sites offering an insight into the cultural, natural and industrial heritage of the Clyde Valley.

Part of the route had deteriorated significantly but challenges around cost, location and landscape meant that traditional surfacing methods were not an option. Mackenzie Construction’s Smart Surface™ was identified as an effective solution with the ability to re-use existing ground materials mixed with a hydraulic binder which resulted in a long-lasting, durable surface.


Prior to works commencing, a 1.3km section of the path surface had deteriorated considerably since past improvement works in the early 1990s with significant areas of mud, water erosion, encroaching vegetation and decayed timber edging. With this part of the route falling in a remote and hard to reach area, this made the importation of quarried aggregate material a challenge. Further challenges presented were around the suitability of traditional surfacing materials. Steep gradients and potential future damage from unauthorised motorbikes meant that whin dust was not a durable enough solution whilst tarmac was not an option due to cost and landscape fit.


Mackenzie Construction’s Smart Surface is an innovative surfacing solution that uses a hydraulic binder, ecoProactive™ to recycle existing ground materials into a long-lasting and sustainable surface. Having been impressed with previous Smart Surface results, and with the pressing challenge of cost, durability and the issue of importing quarried materials, the client opted to use Mackenzie Construction’s Smart Surface.


In this process, the exposed base was rotovated to a minimum depth of 100mm to ensure the substrate material was suitably mixed and that any larger ground material was crushed. The binder was then applied to the surface at an application rate of 7%, before being fully mixed into the prepared base material using the same multi-pass rotovating process. The resultant mixed material is hand raked to required crossfall and compacted to refusal using a typical Type 120 ride-on roller, or larger, where space allows.

To aid the surface finish, a layer of 6mm grit was applied directly to the surface at the time of compaction. This grit can be any colour however it was decided to apply one that was grey in colour to simulate the very familiar whin dust path surface whilst also providing a uniform finish throughout the full route and adding an anti-slip element; something that was of value on the steeper gradients. Whilst the finished path is now impervious to water, and highly durable, an element of open drainage was designed into the project to help keep water off the surface, something that will be beneficial during colder months where water seeping onto the path from adjacent embankments can freeze and make the route treacherous or impassable.

“Steep gradients, surface damage from motorbikes and restricted resources for ongoing maintenance meant that more traditional path surfacing materials would not have provided an effective solution and tarmac was not an option due to cost and landscape fit. The finished path at Clyde Walkway has typically surpassed expectations and, throughout the development and implementation of this project, the project partners were also hugely impressed by the commitment and professionalism shown by the Mackenzie Construction team to deliver the highest quality of end product. We have every confidence that Smart Surface™️ will provide those involved in delivering and maintaining our outdoor access and active travel routes across Scotland with an alternative and genuinely effective solution.”

Graeme Anderson, Technical Officer | Paths for All


The path was successfully restored and in use the following day from works completing. The completed path blends perfectly into the landscape, supporting regular use for many years to come with almost no maintenance required. CBR testing prior to the upgrade was showing a value of 0.2% with post-project testing showing a dramatic increase at 21.7%. The re-use of existing site materials versus importing and exporting new aggregates is estimated to have saved around 60% in carbon emissions.