Milton looks like a growing Halton Region suburb from the highway, but its industrial backbone includes two large projects: an aggregate quarry that has run continuously since the 1960s, and a rail intermodal facility under construction on the edge of town. The quarry already supports active heavy-truck movements. The CN Milton Logistics Hub, currently under construction and expected to open in 2027, is projected to add future intermodal truck activity.
The Dufferin Aggregates Milton Quarry, operated on the Niagara Escarpment since it opened in 1962, is recorded as the largest producing quarry in Canada — the licensed area covers roughly 1,150 acres (467 hectares). Ontario approved a Niagara Escarpment Plan amendment in July 2025 enabling a further quarry expansion of about 30.5 ha. Aggregate haul trucks running in and out of a site like this spend much of their operating life in short, heavy-load cycles rather than steady highway running.
Separately, Canadian National Railway is building the Milton Logistics Hub — an approximately $250-million intermodal facility where shipping containers will transfer between trains and trucks — on CN-owned land near the town's 400-series highway access and CN's mainline. The project is under construction and, according to CN, is expected to begin operations in 2027. Once operating, the federal Decision Statement limits future container-truck activity to a maximum monthly average of 800 container trucks entering per day, and a maximum of 880 container trucks on any single day. Those figures are operational-phase caps for the approved project — not today's measured traffic at a hub that is not yet open.
CN selected Milton because the site is close to its mainline and the 400-series highways, is zoned for employment use, and sits next to a growing cluster of warehouses and distribution centres along Milton's highway corridor.
Duty cycle does not change the legal inspection triggers or opacity limits. It is relevant mainly to maintenance planning and vehicle readiness before the next DriveON test. A heavy-duty diesel commercial motor vehicle with RGW over 4,500 kg still follows the ownership-transfer and plate-renewal triggers published on ontario.ca.
Quarry haul trucks and future intermodal drayage units share a practical logistics concern: an off-site trip to a fixed test centre can add travel, waiting and driver time to the inspection process. Testing may be arranged at an eligible fleet yard or depot in the surrounding Milton logistics area, subject to site access and a safe test location. An authorized mobile DriveON facility and licensed technician perform the official procedure — the standard does not change because the truck was tested at a yard.
Related guides: aggregate & dump truck opacity testing and Hwy 401/25 industrial dispatch. Schedule through Piotr Service.
