February 26, 2010

CITY OF LONDON RENDERING

In an innovative solution, the City of London is building a roundabout over a CN Rail tunnel system

FEATURE | Roadbuilding

London, Ontario hopes roundabout will improve traffic flow, avoid trains

MARY BAXTER

correspondent

LONDON, Ont.

In rail travel’s golden era, the round house was key to helping a locomotive reverse direction. That idea comes full circle in a unique structure intended to improve safety and ease road traffic flow over CN rail tracks in London, Ontario.

Construction begins in earnest this month on an overpass topped by a roundabout – London’s first on an arterial road - that will replace an at-grade crossing at the Hale and Trafalgar Streets intersection.

“There’s a whole lot of fill coming in,” says Jane Fullick, a roads transportation planning and design technologist with the city, of the 52,000 cubic metres of fill that will be needed to flesh out the unusual structure over the tracks.

Once complete, it will measure 86 metres long by 25 metres wide and will provide a grade difference between the current level of the tracks and “where the cars will be” of roughly nine metres, she says.

The city has long debated the need to add another overpass over the busy rail corridor (on average, 47 trains per day use the crossing). But initial plans had called for establishing signal lights.

A reevaluation by consulting project engineers Delcan Corporation two years ago brought the idea to light.

By adopting the roundabout, “we impacted no more properties than we did in the original design of the intersection,” says Fullick. They also shortened the structure length by 40 metres “which saved us $1.1 million.” An added bonus is eliminating maintenance costs that would have come with signal lights.

Fullick says the project will be straightforward but has an aggressive timeline. Work begins Feb. 22 and must be substantially complete by March 2011 to qualify for stimulus funding. That means the base asphalt will have to be in place by the end of November.

“It is a very challenging schedule and if the weather doesn’t cooperate and that delays the project, that could be a problem,” she says.

Sewers were relocated and resized in 2005 in anticipation of the project and CN also moved one of its spur lines last fall to accommodate the structure.

Fullick says there will be some substantial detours and the city is looking at traffic signal adjustments in the area to help.

Overall, the project will cost $16.3 million to complete. London is sharing the costs with CN as well as with provincial and federal governments through infrastructure stimulus funds.

Earlier this month, city council awarded the general contracting tender to London-based McKay-Cocker Construction Limited. The company’s bid of $10,468,934, the lowest of four received.

For the past decade, McKay-Cocker has concentrated on design-build projects primarily related to the automotive industry. About three years ago, however, the company began to focus more on infrastructure projects, says its chairman, CEO and president, Paul Cocker.

The focus appears to have paid off. McKay-Cocker recently completed a water treatment plant in Ridgetown in Chatham-Kent and is currently completing a $50 million project to build a pumping station and reservoir in southeast London.

“We really looked at this (Hale and Trafalgar) project seriously,” says Cocker. “We were pretty pleased (to win it).”

He notes that CN has “very strict limitations on encroachment” and that has had an impact on the choice of shoring and forming systems for the structure’s deck.

At peak, he estimates there will be 40 people working on the project. London-based excavator Blue-Con Inc. is also involved as a sub-trade.

Fullick says as the project nears completion, the city will begin familiarizing commuters with how a roundabout works.

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