Updated - 04th May 2010
Introduction
The N56 Mountain Top to Illistrin Road Phase 2, which was completed in December 2007, is an extension of the Phase 1 realignment completed in 2006, and consists of a 3.5km realignment between the Mountain Top in Letterkenny and a point on the existing N56 North of Coolboy.This section of the N56 is the main artery from Northwest Donegal to Letterkenny and the rest of the county.
The Need for the Project
The section of road upgraded in both phases 1 and 2 was originally of narrow cross-section, had steep gradients and was poorly aligned. The mixture of rural and urban traffic created delays and long queues were common.
The completed works result in a much improved N56 National Secondary Route, over a length of approximately 5km, within the townlands of Carnamogagh Lower, Carnamogagh Upper, Ballaghderg, Fallard or Calhame, Ellestrin or Illistrin Little and Coolboy Big in the County of Donegal.
The 3.5km section constructed as Phase 2 between Mountain Top and Coolboy, incorporates a realignment of the road junctions at Coolboy and Illistrin to provide for a safer interface with the N56, while the new road crossection incorporates a climbing lane to allow passing of slower moving vehicles. Improved vision lines, lining and signing will also improve safety on the N56.
Overview
Phase 1 which was completed in 2006, incorporated the realignment and improvement of 1.4km of the N56 to the northern boundary of Letterkenny culminating in the construction of a new roundabout at the Calhame junction. The contractor for Phase 1 was Wills Bros Ltd.
Phase 2 was designed and tendered by the National Roads Design Office in Donegal Town in 2006. Noel Regan and Sons Ltd. were the successful contractor, with works commencing in early 2007. The construction of the road required the removal of large quantities of peat and their replacement with rockfill. Extensive management of traffic was required as the existing road had to be maintained ‘live’ for the duration of the works.
Phase 2 included the following features:
- The realignment of the existing Glashagh River over a section to enable the construction of the new road.
- The realignment of the junctions at Illistrin to provide a staggered junction in place of the previously existing cross roads.
- The construction of a reinforced concrete bridge, on piled foundations, at Coolboy to replace the old bridge.
- The construction of a ‘slow lane’ or ‘climbing lane’ from Illistrin to Mountain Top.
- The inclusion of footpaths and streetlighting at Illistrin.
- The diversion and undergrounding of various services and the inclusion of road drainage.
The completed works were officially opened by Mary Coughlan, T.D., Minister for Agriculture, Fisheries and Food, on 14th December 2007.
Consultant Engineers Employed On The Project
Donegal National Roads Design Office – Project Management and Road Design
Carl Bro – Bridge Design
Golder Associates – Specialist Soft Ground Consultant
Phase 2 – Construction of Roadworks at Illistrin