Pictured during an inspection of the N59 Derrylea Cycleway in 2010 are (L-R): ROD Managing Director, Jim Thorpe, and TII Director of Network Management, Pat Maher.
Summary
Roughan & O’Donovan developed the design for an off-road, shared-use footpath and cycleway along the entire length of the newly constructed N59 single carriageway at Derrylea, near Clifden, Co. Galway.
This was a pilot scheme for the new Design Manual for Roads and Bridges (DMRB) design standards.
The design was based on the draft National Roads Authority design standard for cycle/pedestrian facilities in rural areas, previously prepared by Roughan & O'Donovan.
Solution
The project allowed us to assess alternative construction techniques, including paver-laid sub-base, to achieve a high-quality and smooth surface finish for the cycleway.
To minimise costs, we used redundant old road pavement, construction tracks remaining from realignment works and existing verges.
Sections across bog/peat areas were constructed using a floating construction technique consisting of:
- Geotextiles laid directly upon the bog
- Capping laid with low ground pressure plant
- A sub-base laid with paving machines
- A single layer of blacktop finish
Highlights
- A first-of-its-kind project designed to provide cyclists and pedestrians with a dedicated segregated facility on a national road scheme
- As part of the project, technical guidance documents were prepared that ultimately led to the publication of a new Design Standard TD 300 for Cycling Facilities in Rural Areas within the Design Manual for Roads and Bridges (DMRB)
