Thunder Bay

Trans-Canada Highway twinning: most obvious path isn't always best

As tweaks are discussed for the twinning of the TransCanada Highway in northwestern Ontario, one highway design expert says there are many factors to consider in road construction, which sometimes means the best or most obvious option can't be used.

Couple says proposed highway twinning that intersects their land should be in a different spot

Ben and Shy-Anne Bartlett at the site proposed for a new bridge over the Black Sturgeon River. (Gord Ellis/CBC)

As tweaks are discussed for the twinning of the TransCanada Highway in northwestern Ontario, one highway design expert says there are many factors to consider in road construction, which sometimes means the best or most obvious option can't be used.

A couple near Nipigon is asking the Ministry of Transportation to move the proposed site of a bridge across the Black Sturgeon River.

The bridge is part of the the twinning project along that stretch of road. 

Ben and Shy-Anne Bartlett say the bridge and highway will have a negative effect on some landowners and could disrupt groundwater. They say it should be moved slightly north. 

But a engineer with the firm LEA Consulting in Markham said they must balance constraints —such as rock cuts, water crossings, and cost — with safety regulations dictating the curve of the road, and the gradient on hills. 

For instance, Rick Baldasti said changing the placement of a bridge may create problems somewhere else. 

"The curves that are coming in and out of that crossing location could be impacted and end up being substandard," he said.

"The geometrics...are defined by the posted speed, and they basically make for a safe highway at the end of the day."