Ontario’s ‘Big Dig?’ What the province can learn from Boston’s mega-highway project | CBC News

As Ontario considers building a tunnel underneath Highway 401, some say the provincial government can learn from a similar highway megaproject south of the border. 

The Boston Central Artery Tunnel project, better known as the Big Dig, involved replacing a six-lane elevated expressway that ran through that city’s downtown core with an underground highway directly beneath the existing one. The elevated highway stayed open  throughout construction until the underground one opened to traffic. The project also extended an interstate highway to Logan International Airport.

“What we did was the equivalent of open heart surgery while the patient continues to go to work and play tennis,” said Peter Zuk, a transportation consultant who was project director from 1991 to 1999. 

“We held up the existing highway at the same time as we built the same level of highway capacity underground.”

Premier Doug Ford says an underground expressway beneath the 401 would ease gridlock on the congested Greater Toronto Area highway by expanding its capacity for drivers and transit. Unlike the Boston megaproject, Ford’s vision is not to replace the existing highway, however.

The premier cited Toronto Board of Trade data showing that Toronto-area commuters spend an average 98 hours each year navigating rush hour traffic.

Congested highway leads to big idea

Boston was also facing a traffic congestion crisis in the 1990s.

Traffic on the central artery “crawled” for more than 10 hours each day, and the accident rate was four times the national average, according to the Massachusetts Department of Transportation.

After years of planning, construction on the Boston project began in 1991. It was soon beset by delays and cost overruns. The price tag ballooned from an initial estimate of $2.6 billion to a whopping $14.8 billion and it wasn’t completed until 2007.

Zuk, who worked as an executive at provincial transit agency Metrolinx from 2017 to 2020, said he’s confident the province has the capability to complete a project of the scale Ford pitched, citing the GO expansion, Eglinton Crosstown and Ontario Line as examples of Ontario’s and Toronto’s credibility on transportation projects.

Similar to the Big Dig, Zuk said the 401 project would face the challenge of engineering a way to support the existing highway structure while also tunneling below. He said a comprehensive traffic management plan would be necessary to ensure the same throughput of traffic during construction, and a plan to mitigate disruptions to nearby residents and businesses. 

“All of these are part of the playbook of the modern infrastructure projects and it’s a playbook that the province is already writing a lot of itself,” Zuk said.

Transparency on cost is vital, expert says

To avoid some of the pitfalls of the Boston project, Zuk said transparency will be key.

“It was not very transparent in the early days of the Big Dig,” Zuk said. “When it did become transparent what the cost would be, we had lost credibility in terms of the cost number.”

Zuk said being open about the true cost and benefits of the project from the outset will allowing governments to make an informed decision about whether to proceed and help maintain public support for the project.

Ford pledged Wednesday to be transparent construction costs, though his government has repeatedly refused to disclose the estimated costs of building the new Highway 413. He said he’s confident Ontario can avoid some of the challenges of the Boston project faced.

“They had different firms working on it. They had old wires and pipes that they didn’t realize … They were hitting frost underneath. That’s not going to happen here,” he said.

Beyond transparency, “generational” projects like the Big Dig require a broad coalition of supporters that will keep them alive in the face of public opposition and changes in government, said Ian Coss, host of the podcast The Big Dig from Boston-based public media outlet GBH News.

Coss said that means politicians of different parties, residents, interest groups, business, environment and labour.

“It can’t be just like the lone quest of one person. It can’t be a vanity project because it won’t survive,” Coss said. “The Big Dig barely survived by the skin of its teeth, right? It was nearly killed half a dozen times.”

In the end, Coss said the Big Dig did fulfil much of its promise. He said it reconnected the city’s waterfront to its downtown, created 6.9 hetares of greenspace and led to an improvement in driving times.

WATCH | Toronto’s Big Dig? Ford promises 55-km traffic tunnel under Highway 401:

Toronto’s Big Dig? Ford promises traffic tunnel under Highway 401 across GTA

Ontario Premier Doug Ford’s proposed plan to build a tunnel under Highway 401 in the Greater Toronto Area has some experts comparing it to Boston’s infamous Big Dig — a tunnel project beset by delays and cost overruns that took 25 years to complete.

A study by the Massachusetts Turnpike Authority, the state transportation agency, found the Big Dig cut the average trip through Boston from 19.5 minutes to 2.8 minutes.

“It did reconnect the city, it did improve transportation. But that doesn’t necessarily mean that every big project is a good idea,” Coss said.

Ontario’s Ministry of Transportation will now conduct a feasibility study on the 401 tunnel proposal that will look at the potential economic benefits, traffic impact, soil composition and best practices from other jurisdictions.