OTTAWA, Ontario — Canada's Parliamentary Budget Office estimates the proposed Alto high-speed rail project linking Toronto and Quebec City will cost between Ca$75 billion and Ca$113 billion, a range substantially above the figures the project's own leadership has cited.

The estimate, published Oct. 1 in a report requested by the Senate Committee on National Finance, is roughly $53 billion to $79 billion in U.S. currency. It compares with a projection of Ca$60 billion to Ca$90 billion offered by Alto CEO Martin Imbleau in early 2025 — a gap of up to Ca$23 billion at the top end.

The budget office says the wide range "reflects the considerable uncertainty inherent in large-scale rail infrastructure projects." Its modelling assumes the Canadian planning and approval process will follow the pattern of comparable European projects. That assumption matters for the cost outcome: the report notes that similar undertakings in the United Kingdom and the United States have run significantly higher on construction costs, citing land acquisition, litigation, permitting difficulties and project management failures as likely causes.

Canada has passed legislation intended to address those risk factors, according to the report, but the PBO cautions that the legislation's fate in court and its practical effectiveness will be decisive in controlling the project's financial exposure.

The economic payoff, on the budget office's measurement, would be limited during construction. The report projects a "modest" stimulus effect: gross domestic product would rise by $1.8 billion to $2 billion between 2029 and 2033, with 4,300 to 9,000 jobs created. Those figures are projections, not measured results, and cover the construction phase only.

This is the first of two PBO analyses of Alto. A second report will assess whether projected ridership can support operation of the service — the central question for the project's long-term financial case, given that revenue depends entirely on demand along the approximately 1,000 km corridor.

The federal government committed to the project in February 2019 under then-Prime Minister Justin Trudeau. Prime Minister Mark Carney's government continues to back it. Political durability is not guaranteed: the opposition Conservative Party has said it would cancel the programme if it takes power, and many communities along the route — which would see no direct benefit given Alto's limited stops — remain strongly opposed.

For the project to proceed at the lower end of the PBO's range, Canada will need to keep its approval process closer to the European model than to the litigious, high-cost precedents of HS2 in Britain or U.S. megaprojects. The Senate committee, and the public, now await the budget office's ridership analysis to judge whether Alto's operating case can carry the capital burden the new estimate implies.