● FRI, MAY 1 · TODAY · PLAN AHEAD ●★
416TRAFFIC
ConstructionFri, Apr 24, 2026 – Wed, May 20, 2026HWY 400 (Southbound)

Nightly Engineering Investigation on HWY 400 Southbound between ST VINCENT STREET and SUNNIDALE…

Construction · Fri, Apr 24, 2026 – Wed, May 20, 2026
★ IMPACT 5/5 · ★ SOURCE-BACKED CLOSURE RECORD

★ Quick facts

Location
Between ST VINCENT STREET and SUNNIDALE ROAD
Start date
Fri, Apr 24, 2026 · 11:00 PM
End date
Wed, May 20, 2026 · 5:00 AM
Lanes affected
2 Right Lane(s)
Severity
Severe
Source
Ontario 511Event ID 239759

What's affected

HWY 400 (Southbound) between ST VINCENT STREET and SUNNIDALE ROAD is impacted by construction work. Expect impact to 2 Right Lane(s).

Suggested detour: Highway 27 and Yonge Street are the practical alternates south of King City; both are heavily congested in peak.

Same-day events

Plan ahead

Read next

★ RoadHighway 400 statusSegment-level closures, long-running restrictions, and upcoming work.read →★ DayTraffic on Fri, Apr 24, 2026Same-day events and other road restrictions around this closure.read →★ ClosuresAll road closuresBrowse active and upcoming construction records.read →