�ȵ����

It may not be quite a feat of engineering, but building a new road right over Highway 404 in York Region does come with a list of challenges.

First identified as a need in master transportation plans dating back approximately 20 years, the road will connect the existing intersections of Leslie Street and Orlando Avenue in Richmond Hill and Woodbine Avenue and Markland Street in Markham.

Designed by GHD Consulting, which is also the contract administrator, the road is being built by Brennan Paving & Construction Ltd. Construction started in the summer of 2023 and is expected to continue to the summer of 2026.

Known as the Highway 404 Midblock Crossing, the $114-million project is a three-way joint-funding partnership between York Region and the municipalities of Markham and Richmond Hill in co-operation with the Ministry of Transportation (MTO).

This is not an interchange, emphasizes York Region senior project manager Lloyd Fernandes.

Making the leap over the expressway will be achieved through the construction of a, now well underway, 23.7-metre-wide, 80-metre-long, two-span bridge with four traffic lanes and multi-use pathways using 22, 40-metre-long, pre-stressed 1900 CPCI concrete girders.

In a carefully co-ordinated two-night operation in November of 2024, Brennan Paving installed 11 girders over the northbound lanes on the first night and then another 11 girders over the southbound lanes the second night using strategically placed cranes, says Fernandes.

During the week of installation, the contractor built a temporary granular pad for one of the cranes on the east side of the highway and then on the evening of the lift a second crane was positioned directly on Highway 404. The girders were staged along the highway shoulder with delineation to protect motorists, he says.

“Each girder took about 30 minutes to install. There were a series of rolling closures along the highway. Once one girder was in place, the OPP would escort traffic ahead until it was time to install the next girder.”

Supporting the bridge is an approximately seven-metre-high (column and cap) concrete centre pier the Ministry of Transportation agreed to incorporate as part of its own project to widen Highway 404 in that area. It was installed in 2023. Having the pier in place well in advance of the bridge work minimized construction costs, time and disruption to commuters, he says.

The road surface on the new bridge is approximately 9.5 metres above Highway 404, accounting for girders, deck, asphalt and waterproofing.

As construction of bridge over Highway 404 is just one element of the project, multiple crews are onsite.

“Rather than one peak, there are multiple critical phases requiring a concentrated effort.”

Soon-to-get underway will be the construction of a new single-span 25.5-metre-wide, 60-metre-long bridge with nine 60-metre-long I steel girders and a concrete deck over the Rouge River.

Also included in the project will be the reconstruction of some streets and the reconfiguring of others which will link with the new road, plus the installation of a new signalized intersection of the north extension of Cachet Woods Court and New Collector Road, and a second signalized one at New Collector Road and Markland Street.

“Safety is paramount, especially during the girder placement over a live highway,” says Fernandes, when asked about the overall project challenges.

For motorists driving along Highway 404 and the adjacent roads there are and will continue to be impacts including lane reductions and closures, he says.

When complete and fully operational, however, the new road will provide direct access for residents and businesses to the east and west sides of Highway 404 and help reduce traffic volume on major arterial and local roads.

The inclusion of sidewalks and paths will also be the stimulus for other non-vehicular traffic including walking, cycling and micro-mobility travel, says Fernandes.

Another benefit is enhanced protection for the Rouge River floodplain. Last year more than 10,000 trees, shrubs and grasses were planted and that will help improve storm water quality, he says.

As might be expected for a project of this magnitude and complexity, considerable planning was required.

That planning got underway in earnest with a Municipal Class Environmental Assessment in 2014/2015, with design starting in 2016.

Detailed consultations were conducted with the MTO regarding the overall design and the centre pier.

The MTO was just one of multiple local, regional, provincial and federal agencies as well as with private property owners who provided input.

Even Transport Canada and Nav Canada had to be consulted. Although it’s now closed, the potential impact on the nearby Buttonville Airport had to be assessed, he says.

This isn’t the first time York Region has built a road over Highway 404. Just south of this site is Norman Bethune Avenue, which was installed in 2018.

“It was a similar bridge and similar set up and the lessons learned on that project were applied to this one,” says Fernandes.