CR4 and 9th Line Innisfil Roundabout

The County of Simcoe is constructing a roundabout at the intersection of County Road 4 (Yonge Street) and 9^th Line in Innisfil.  The roundabout will have a two lane configuration to accommodate the future widening of County Road 4 to four lanes (two lanes per direction of travel).  Benefits of the roundabout include improved traffic flow, increased traffic capacity, and enhanced safety due to lower vehicle speeds and fewer vehicle conflict points.  The County will be coordinating with InnServices to install water and sewer mains during road construction.

Timeline

• Utility relocations: Winter 2024/2025
• Tender release: Spring 2025
• Construction start: Summer 2025

Project Update (Nov 2025): Construction began in July 2025. Some base course asphalt is anticipated to be completed by late fall 2025, allowing the intersection to remain open throughout the winter. Final roundabout work, including the concrete curbs and splitter islands, top course asphalt, and permanent line painting, is scheduled for completion in Spring/Summer 2026.

Impacts to Drivers & Neighbours

• 9th Line (County Road 4 to 20th Sideroad) shall be closed from September 2 to November 30.