Accessibility Tools

Iroquois and Long Sault Roundabouts


United Counties of Stormont, Dundas, and Glengarry


Village of Long Sault, Ontario
Village of Iroquois, Ontario

Construction Value




Key Features

  • Two rural roundabouts
  • Heavy vehicle accommodation measures
  • Pedestrian and cycling considerations
  • Traffic calming measures to address high speed characteristics of project sites

Project Description

Robinson Consultants Inc. was retained by the United Counties of Stormont, Dundas and Glengarry to complete the preliminary and detail design for the reconstruction of County Road 2, through the Village of Long Sault, including two roundabouts, and the design a proposed roundabout at the intersection of Country Road 2 and County Road 1, in the Village of Iroquois as joint project. The key purpose of the project was to address the high-speed characteristics of the project sites along County Road 2, a former MTO highway with design characteristics (e.g., flat/straight alignment, wide open corridor) that resulted in significant concerns with speed and safety.

For the intersection of County Road 2 and Country Road 1 in Iroquois, the specific challenges associated with this intersection included the approaching curvature of the County Road 2, which resulted in limited approaching visibility and the skew of the existing intersection which hindered the accommodation of heavy vehicles right-turn movements. To ensure adequate advanced indication of the facility to approaching motorists, a minor realignment of the approaching roads, coupled with the extension of the splitter islands were utilized. The accommodation of heavy vehicles required expansion of the roundabout’s inscribed circle diameter (ICD); however, in order to mitigate increased operating speeds of the facility, Robinson Consultants Inc. proposed external truck aprons to balance the need for large increases to the ICD with the anticipated passenger vehicle operating speeds. 

The project was the first roundabout for the Village, as well as the United Counties, therefore public outreach was included in the project, which included a public information session. To demonstrate the roundabout operations, a short video simulation of the future intersection was prepared by Robinson Consultants Inc. and displayed at the information session with County Staff and design team representation to address any questions or concerns that arose.

The key purpose of the reconstruction of County Road 2, through the Village of Long Sault was to address the high-speed characteristics of the roadway and provide streetscaping enhancements along the corridor reflect the surrounding community. The high-speed characteristics of County Road 2 formed a barrier between the community and the Waterfront Park and Trail. The corridor improvements included a reduction in the existing four-lane undivided cross-section to a two-lane divided cross section; complete with a planted centre median and pedestrian and cycling considerations and the design and construction of two single lane roundabouts that promote traffic calming and serve as a gateway to the community.

As the existing County Road 2 corridor was a former MTO highway through both Iroquois and Long Sault, the existing granular road base was found to be more robust than the current loading requirements, as such, Robinson Consultants Inc. was able to refine the roadway sections and profile to utilize the existing roadway structure to the greatest extent possible.  The utilization of the existing road structure resulted in a considerable reduction in the requirement for imported material, resulting in considerable capital savings to the Counties.


2018 CEO Award of Excellence