There wasn’t any cake and champagne celebration this summer but residents and elected officials in Milton, Ont. are applauding an almost completed road project designed to remove one of the town’s major traffic bottlenecks.

001_RBI-image-1009625Although sidewalks have to be built and site restoration and landscaping undertaken, the $31-million Derry Road underpass just west of Bronte Street has been completed and is now being used by motorists in the southwest quadrant of the town.

Construction started in 2013 and it was overseen by Burlington, Ont.-based New Alliance Limited. The consultant was R. V. Anderson Associates Limited.

Trains on north-south CN tracks, which had previously crossed the Derry Road at grade halting traffic, now pass overhead on an 11-metre-wide cast-in-place rail bridge. Just a little to the east of bridge is the Milton District Hospital.

New and planned development in the western portion of the town combined with increased traffic volumes on both the rail lines and the road was the impetus for the grade separation, says Tim Dennis, Halton Region engineering and construction director.

“Derry Road is an important arterial road connecting with Hamilton to the west and to the east with Mississauga and Peel Region.”

A 2006 environmental assessment concluded the underpass was necessary to satisfy east-west capacity requirements, to reduce delays and to improve safety for cyclists, pedestrians and vehicle traffic, he points out.

“This is not our largest project and we (the region) have done other grade separations, but it was a significant project.”

Prior to construction, Milton Hydro, Union Gas and Bell Canada had to relocate their lines and the region also had to relocate two of its watermains, he says.

Although there were no environmental constraints, there were some major engineering challenges.

“Storm water management was a significant issue,” says Dennis, citing the need to install a 4,200 cubic metre storm water detention tank under Derry Road, and an adjacent dewatering pumping station and two oil and grit separators.

During construction, traffic was detoured outside the excavation limits on a temporary road on the south side. There were, however, times the area had to be totally blocked off for short duration “strategic milestones,” necessitating a detour of traffic to other roads.

Those milestones included a temporary diversion of the CN tracks so the bridge could be built and then moving the tracks back to their original alignment, he says.

Constructing the underpass was a staged procedure which required a partial excavation, followed by the pour of the supporting caissons, the erection of the bridge, and then further excavation, says New Alliance assistant project manager Natalee Rodrigues.

The actual moving of the railway lines was handled by CN crews, says Rodrigues, noting that a major project challenge was the co-ordination required among CN, Halton Region, and Town of Milton officials.

“We will have to close the road for about 24 hours for the final layer of asphalt,” says Rodrigues, who expects that to occur near the end of August.

Site restoration will be completed as part of the current contract. But detailed landscaping and tree planting will be tendered separately and completed by a separate contractor who specializes in that type of work, says Dennis.

“I am looking forward the completion of the sidewalks, bike lanes and landscaping this fall,” says Colin Best, Milton councillor, who is also the vice-chair of Halton Region’s planning and public works committee.

The contractor and regional staff had to contend with a number of hurdles including working through two of Ontario’s harshest winters in many years and keeping road and rail traffic moving through the construction site, says Best.

Source: Daily Commercial News