The headline estimate: $75 billion to $113 billion
The Parliamentary Budget Officer estimates that construction of the baseline Alto high-speed rail route between Toronto and Quebec City could cost approximately $75 billion to $113 billion in 2024 dollars. That is above the federal government’s current $60 billion to $90 billion estimate. The PBO stresses that the range reflects substantial uncertainty typical of very large rail projects rather than a final project budget.
The estimate does not include the possible Kingston route change
A major caveat is that the PBO model uses the baseline route and does not include the federal government’s June 2026 direction to assess a southern option that could pass through Kingston. The PBO says that amendment could change both engineering difficulty and environmental or population-density constraints, adding another layer of uncertainty before a final alignment is chosen.
| Cost driver | PBO estimate or assumption |
|---|---|
| Baseline construction cost | $75B–$113B |
| Federal estimate | $60B–$90B |
| Extra kilometre of tunnel | about $169M, range $142M–$196M |
| Extra kilometre of elevated structure | about $153M, range $132M–$175M |
| Delay of one additional year | about $1.5B more, range $1.1B–$2.0B |
| Assumed new HSR-capable track length | up to about 850 km |
Why tunnels are so expensive
High-speed rail requires gentler curves and grades than conventional rail, which limits how easily a route can follow existing terrain. Dense urban areas also create barriers. The PBO assumes roughly 15 kilometres of tunnel may be required to connect Laval and Montréal. Every additional tunnel kilometre carries a very high unit cost because excavation, ventilation, safety systems, stations or portals and complex construction logistics all have to be delivered together.
The Canadian Shield is another engineering challenge
The analysis identifies roughly 130 kilometres between Ottawa and Peterborough that could encounter Canadian Shield terrain. Building a route designed for trains travelling up to 300 km/h across rock can require extensive cutting, grading and filling. That work is cheaper than full elevated structures in the model, but materially more expensive than straightforward surface construction.
Delays can add billions even before scope changes
The PBO’s international dataset suggests that each additional year before construction begins is associated with approximately $1.5 billion in additional construction cost, after controlling for tunnels and elevated structures. That does not mean every one-year delay automatically produces exactly that increase, but it shows why schedule risk is a financial issue rather than merely a political inconvenience.
Project management may matter more than geology
One of the report’s most important findings is that institutional and project-management risk can outweigh pure engineering risk. Land acquisition, permitting, litigation, late design changes, non-standardized designs and weak delivery capacity all contribute to escalation. The PBO notes that recent federal legislation may streamline some approvals, but it does not eliminate those risks.
What about economic benefits?
The PBO estimates construction would provide a modest near-term economic boost. For the Ottawa–Montréal segment, it estimates real GDP would be about $1.8 billion higher in 2029 and $2.0 billion higher by 2033, while annual employment effects rise from roughly 4,300 to 9,000 jobs. These are annual level effects, not cumulative totals, and they do not include productivity benefits after trains begin operating.
The biggest unanswered question is ridership
This report is only the first part of the PBO’s assessment. A later report is expected to examine whether projected ridership can support operations. That matters because a railway can create broad economic benefits while still requiring public operating support. Construction cost tells only one side of the value-for-money question.
Bottom line
The $75B–$113B range should be read as a warning about uncertainty rather than a final invoice. The final route, tunnel length, urban approaches, construction start date and project-management discipline will all move the number. The key question for Canadians is not simply whether the project is expensive, but whether its final benefits, ridership and network effects justify the full lifecycle cost.