A familiar Ontario highway habit becomes legal on six more stretches today. As of August 31, 2026, the province is permanently raising the posted limit from 100 km/h to 110 km/h on five sections of Highway 401 and one section of Highway 403. The changes are part of a much larger summer rollout that will add 938 kilometres of higher-limit highway and, once the final September changes take effect, put 110 km/h signs on nearly 89 per cent of the provincial freeway network.
For drivers, the practical change is simple: the sign now permits another 10 km/h. The bigger story is how Ontario is knitting together previously separated 110 km/h zones while keeping the most congested or constrained stretches under lower limits.
Merlin Road to Highway 427: A Major Western Corridor Goes 110
The biggest change taking effect today is on Highway 401 from Merlin Road in Chatham-Kent to Highway 427 at the western edge of Toronto. That covers a long, heavily used corridor connecting southwestern Ontario with the Greater Toronto Area, passing freight and commuter markets around London, Kitchener-Waterloo, Cambridge, Milton and Mississauga. The province says Highway 401 moves more than $380 million worth of goods on an average day, underscoring why changes on the route attract attention beyond daily commuters.
The new 110 km/h limit does not mean traffic will suddenly flow at that speed everywhere. Congestion, construction, weather, collisions and lane closures can all force slower travel, particularly as the highway approaches the GTA. The legal change simply raises the maximum posted speed where conditions permit. Drivers still have to adjust to road and traffic conditions, and the 100 km/h limit remains on Highway 401 beyond Highway 427 through Toronto.
Highway 404 to Highway 35/115: The Eastern GTA Link Speeds Up
East of Toronto, the Highway 401 section from Highway 404 to the Highway 35/115 interchange also moves to 110 km/h today. This is an important piece of the corridor because it carries traffic out of the Toronto area through Durham Region toward Clarington and eastern Ontario. The change brings the posted limit on this stretch closer to the 110 km/h zone already in place from Highway 35/115 to Cobourg since Ontario’s 2024 expansion.
For regular eastbound travellers, that means fewer abrupt transitions between 100 and 110 km/h as they leave the GTA. Ontario says the sections chosen for higher limits have gone through technical reviews and, where needed, infrastructure improvements before signs are changed. That does not remove the need for caution around interchanges and merging traffic. The 10 km/h increase is a legal ceiling, not a target drivers are expected to maintain regardless of congestion, visibility or road conditions.
Cobourg to Colborne: A 100 km/h Gap Disappears
The gap between Cobourg and Colborne is another Highway 401 section switching to 110 km/h. On a map, it may look modest compared with the much longer western corridor, but it has an outsized effect on continuity. Ontario had already raised the limit to 110 km/h from Highway 35/115 to Cobourg and from Colborne to Belleville, leaving this portion between two higher-speed zones. Today’s change effectively stitches those pieces together completely.
That matters for drivers who regularly travel between the eastern GTA, Northumberland County and the Quinte region. Instead of encountering a lower posted limit between two 110 km/h areas, motorists will see a more consistent speed regime across a longer part of the route. Ontario began testing 110 km/h limits in 2019, made six southern highway sections permanent in 2022 and expanded the program again in 2024 before the much larger 2026 rollout now reshaping the provincial network today.
Belleville’s Sidney Street to the CNR Overhead Bridge
A shorter Highway 401 stretch through Belleville is also part of today’s change: Sidney Street to the Canadian National Railway overhead bridge. This segment sits inside a corridor where surrounding sections had already moved to 110 km/h, including the Colborne-to-Belleville and Belleville-to-Kingston stretches announced in the province’s 2024 expansion. Raising the limit here reduces another small break in the higher-speed pattern across eastern Ontario.
Short gaps can matter more than their length suggests because drivers respond to changing signs, interchange activity and local traffic conditions. A more uniform posted limit can make the legal expectation easier to understand, but it does not eliminate local complexity. Belleville-area traffic includes commuters, long-distance travellers and substantial commercial movement along Highway 401. Drivers still have to watch for merging vehicles, work zones and temporary restrictions, all of which override the practical benefit of a higher posted maximum when conditions are busy or disrupted today.
County Road 38 to Highway 15: Kingston-Area Continuity
The Highway 401 section from County Road 38 to Highway 15 is the fifth 401 segment moving to 110 km/h today. It helps close another eastern Ontario gap near Kingston, where the surrounding corridor has been converted to the higher limit. In 2024, Ontario raised the limit on the Belleville-to-Kingston section, and on June 26, 2026, the province increased the Highway 401 stretch from Highway 15 to Highway 16 to 110 km/h in the first phase of this summer’s rollout.
The result is a continuous higher-speed corridor through a region that functions as a key link between Ontario, Quebec and cross-border trade routes. Ontario has described Highway 401 as a critical transportation artery, carrying roughly 10,000 trucks and up to $380 million in goods on an average day. For passenger vehicles and freight alike, consistency can simplify trip planning, but posted speed remains only one factor in actual travel time.
Highway 401 to Middletown Line: Highway 403 Joins the Change
Highway 403 joins today’s expansion, with the section from Highway 401 to Middletown Line moving to 110 km/h. It is the only Highway 403 stretch in the August 31 group, though the province scheduled additional Highway 403 changes for September 30 as the summer program reaches its final phase. Ontario says the 2026 expansion adds 938 kilometres of 110 km/h highway and follows earlier permanent increases introduced in 2022 and 2024.
The higher limit does not relax enforcement at the top end. Ontario law treats driving at 150 km/h or more as stunt driving anywhere in the province, including on 110 km/h freeways. Ordinary speeding penalties also continue to apply above the posted limit. That distinction is important: 110 km/h is now legal on this section, but 120 or 130 km/h is still speeding. The province says it will continue monitoring operations and safety performance where higher limits are introduced.
