M7 Portlaoise By-Pass

Togher Interchange

The Togher interchange is the most important feature of the entire scheme. It is the point of intersection of all the major routes. The scale and treatment of the interchange is intended to reflect this fact.
The interchange has a strong oval form, which is generated by the functional requirements of the various route ways. Within this oval, a series of terraces have been created, which are planted with bands of material to emphasise their form. The earth terraces are off-centred in relation to the oval interchange, thus creating a spatial tension.
The planting, consisting of Norway Maple, Red and Yellow Dogwood, enframes the view of the sculptural elements, in both the eastbound direction, and the westbound direction, adding a contextual relationship between the art of the sculptural piece, the engineering of the motorway, and the character of the surrounding landscape.
 

Ballydavis Interchange

The Ballydavis interchange is the second major landmark along the motorway. It consists of a large cutting, with the overpass and the western end. The vegetation in the cutting consists of alternating bands of Larch and Dogwood/Spindle.
The bands of vegetation are proportionately spaced from each other using the Fibonacci series, in order to develop a spatial rhythm, which can be read from a passing vehicle. The punctuation of the alternating bands is ascending in the westbound direction, and descending in the eastbound direction, with two single bands at the western ends.
This feature is intended to generate a dynamic experience of motion, in attempt to highlight and accentuate the importance of the interchange as a landmark.
 

Heath Interchange

The Heath interchange is the first major interchange along the route corridor from Dublin. The 'entrance' into the interchange is distinguished by alternating stands of Japanese Larch and Dogwood. In the autumn, these plantings will turn a rich red (Dogwood) and butter yellow (Larch), providing a dramatic backdrop to the engineering structures, and reducing their visual impact to an acceptable level.
During the rest of the season, the difference in height between the bands will provide exciting dynamic for the vehicle- based observer in motion along the carriageway. The alternating bands are continued into the main part of the interchange for eastbound traffic. On the opposite side, the planting of Dogwood is pulled into the sweep of planting, with a stand of Birch rising up behind. The ring fort which was present on the original site is acknowledged by use of an earth mound planted with Hawthorn, which is set in a sweep of meadow.
Standard feathered elms line the sides of the exit/ entrance ramp, and accentuate the flowing lines of the road.