Ontario’s Ministry of Transportation is moving ahead with planning work for Highway 401 improvements between Lake Ridge Road and Salem Road, a heavily travelled section at the Ajax–Whitby boundary.
The near-term proposal would add a fourth continuous westbound lane from the Highway 412 on-ramp to the existing four-lane section at the Salem Road interchange. The ministry says the additional lane is intended to provide congestion relief on a corridor that regularly narrows and backs up.
Environmental and design work comes first
The project is still in the planning and design stage. Environmental effects must be studied and measures identified to manage those effects before construction can proceed.
Ajax MPP Rob Cerjanec described the planning step as positive but cautioned that detailed design work must be completed before improvements can be built. No construction start date was included in the information available September 2.
The westbound section is a well-known bottleneck because traffic from Highway 412 and Lake Ridge Road joins Highway 401 shortly before the highway reaches the wider cross-section near Salem Road.
What drivers should know
The announcement is a planning milestone, not notice of an immediate lane closure or construction launch. Drivers should continue to use current Ontario 511 information for active roadwork, closures and traffic conditions.
More detailed information, including the design, environmental review, construction schedule and traffic-management plan, is expected as the project advances.
Sources: Durham Radio News, September 2, 2026; Durham Post report on the ministry’s project description.
