The REM is going to cost taxpayers a lot more than was initially stated.

When it was first proposed, the Caisse de Depot was going to building, own, and manage the light rail line in Montreal with about $3 billion in funding from the federal and provincial governments, the city of Montreal, Hydro Quebec, and the ARTM (the regional transit authority), while putting up about half the cost itself.

But it turns out that once the train lines are up and running, the provincial government and several municipal governments will be on the hook for up to $8 billion in operational payments over a 20-year period.

The Caisse expects that REM passengers will pay $3 billion for their tickets over two decades.

The Canadian Press reported the contract details earlier this week, and Transportation Minister Andre Fortin confirmed the total cost late Tuesday during debate in the National Assembly.

The reason for the compensation is determined by how the Caisse expects to be paid for operating the REM, and how much profit it needs to make from each passenger.

The Caisse is expecting to earn $0.72 per passenger/km which will be paid by Montreal's Regional Transit Authority, the ARTM. One-third of that amount will come from the cost of an REM ticket, while the remainder will be paid by governments: the province paying 85 percent, and municipalities paying 15 percent.

According to figures obtained by the Canadian Press, the Caisse expects it will cost anywhere from 19 to 24 cents per passenger/km to operate the REM. The rest of the money paid by the ARTM will go toward maintenance costs and ensuring the Caisse earns an 8 to 9 percent profit from the project.

Traffic projections for the REM show the Caisse expects to get $500 million per year in 2028, and more than $700 million per year in 2042.

Opposition councillors denounced this payment scheme on Tuesday, saying it proves the REM will be a privately-run transit service.

Construction on the REM will require weekend closures of the Deux-Montagnes train line for an undetermined time, as well as the closure of the Mascouche and Deux-Montagnes train lines between downtown Montreal and TMR for two years.