The price tag for the city’s downtown transit tunnel will grow clearer after city council approves the alignment on May 27, according to transit committee chair Alex Cullen.

The city’s transit committee approved the staff-recommended downtown transit tunnel alignment on Wednesday, despite some councillors’ concerns that the cost of the tunnel is still too vague.

“When I questioned the cost of the tunnel, I did not feel I got the answer that I needed to hear,” said Kitchissippi Coun. Christine Leadman. “I don’t feel this has been fully fleshed out enough for us to make a decision.”

The staff-recommended alignment would extend the eastern opening of the tunnel 700 metres further than the original alignment.

Leadman said it was not clear how that would impact the cost of the tunnel, and questioned how much it would cost to abandon the existing Transitway infrastructure between the Rideau Centre and Campus Station.

The cost of the tunnel has been pegged at $600 million by what is called a “Class D” estimate.

“This is normal in evolution of a project,” said Cullen. “You go from broad concept to defined concept, to design level, to procurement. Each step as you go the numbers get better and better.”

Latest From ...