Galway Road Network Design
Location: Galway, NL, Canada
Client: DEWCor
Duration: 2015-2018
Key Staff: Michael MacDonald, Kevin MacDonald, Florence Allaire
Project Description
Aerial footage of the completed Galway roundabouts.
In 2015, Harbourside Transportation Consultants was hired to provide the consulting design services to assist with the creation of three multi-lane roundabouts. These were to be constructed in the Galway development in St. John’s. HTC’s scope of work as transportation engineers was for preliminary and detailed design of the three roundabouts and the roadway between roundabouts ‘A’ and ‘B’.
This project featured the interests of multiple stakeholders and was delivered on very tight timelines. Overall, it was an excellent demonstration of Harbourside’s transportation engineering ability. The final roundabout designs showcased flexibility and a dedication to quality deliverables.
Harbourside’s Role
The scope of work for the design included the following.
HTC designed the alignments, auxiliary lanes and section elements. This included pavement, profile, cross fall transitions and supporting infrastructure.
Prepared drawings in Civil 3D for clearing limits, and daylight lines. The goal was to minimize the clearing and property requirements.
Specific attention was paid to areas near streams, water crossings, wetlands, water transmission mains and developed areas.
HTC designed the interchanges and alignments in accordance with NLDTW standards, and the TAC Geometric Design Guide for Canadian Roads.
Harbourside developed and optimized the horizontal geometry of the roundabouts. This was in respect to capacity, safety, construction costs and property impacts.
Considerations that influenced this optimization included the vertical profile,
sight distances, utility locations and property.Harbourside provided the horizontal geometry and curb layout for the roundabout. Predesign was done in AutoCAD using the UK Design standard (TD 16/07).
HTC completed the detailed design of the connector road and three roundabouts. At the Ruth Avenue interchange the roundabouts were labelled ‘B’ and ‘C’. The roundabout in the commercial development was labelled Roundabout ‘A’.
Harbourside created the Roundabout signage and pavement marking drawings. These included all roundabout guide signs and regulatory signs.
Specified sight distances and landscaping restrictions (sight triangles), entry angles, and fastest path analysis for the roundabout. This was done in AutoCAD with diagrams for submission to NLDTW, Mount Pearl, and St. John’s.
Completed the turning movement diagrams for the design vehicle, as specified by NLDTW.
Harbourside prepared the contract drawings and tender quantities for the roads and roundabouts.
Lighting layout drawing.
Accommodation for pedestrian facilities.
Location of Storm drainage inlets.
Liaison with NLDTW, St. John’s and Mount Pearl.
Unique Challenges
In addition to the technical challenges of designing multi-lane roundabouts, the inclusion of multiple stakeholders required additional communication and robust response time. The developer, two municipalities, the Provincial Department of Transportation and the municipal services consultant all had to be kept apprised of development. Coordinating between these parties required skillful project management at every stage.
This was in combination with the fact that the design was delivered on an extremely accelerated schedule. Altogether, the Galway Roundabouts showcase how Harbourside can deliver high-quality in all situations.
Social Impact
In creating these roundabouts, the city of St John’s becomes more interconnected, and easier to traverse. The Galway development is now accessible through its Mount Pearl connection, improving transportation throughout the city. The modern features of the roundabouts also make them more robust, safer access points when compared to classic intersections.
