Don’t believe the pessimists. There’s enough money to expand rail transportation in Miami-Dade County.

In one fell swoop, the trust that administers the half-cent sales tax surcharge, the Citizens’ Independent Transportation Trust (CITT) has silenced those who say that Miami-Dade County leaders are not willing to abide by our promises to build a true rapid-transit system.

Here’s what six courageous and honest board members did, during a special session convened by the board president:

—They rescinded the 2009 resolution of a prior board that allowed the county to use surcharge funds for maintenance and operations of the existing system. This was during the Great Recession of 2008. The current board of the CITT said that, beginning in the fiscal year 2019-2020 budget, the county cannot use what has been an average of $100 million per year, since 2003, for anything other than expansion of rapid transit.

—The CITT board set in motion a legislative mandate that effectively forces the County Commission to also rescind prior resolutions allowing the misuse of the money. Here’s how it works: If, on first consideration, the commission rejects the mandate of the CITT board, the board can issue it a second time. This time the County Commission can only reject the mandate by a two-thirds vote. That is a practical impossibility.

—Anticipating Mayor Carlos Gimenez’s renewed promise to “unwind unification” — stop using what are supposed to be capital funds for maintenance and operations — the CITT board recites what is the latest of those promises: to stop the diversion of funds by the year 2023.

The year 2023 is just two years before the surcharge was to have ended its useful life. Perhaps for that reason, we are now informed, that after two decades from when the money started being collected, it will simply not happen. There are no funds, we are told, to build the $3.6 billion SMART Plan, which would add more than 60 miles to the rail system, using at least five new rail corridors: north along Second Avenue to Hard Rock Stadium, south from Dadeland to Florida City, east-west along State Road 836, downtown to South Beach via Baylink, and along the FEC line that runs along Biscayne Boulevard from downtown to Aventura.

Those pessimistic pronouncements ended with the CITT’s actions on Aug. 23. Instead, what we see now is the prospect of a stream of revenues, using existing taxes, that will have an enormous bondable capacity.

Let’s quantify that.

The CITT has used revenues to issue bonds so efficiently that its “multiplier” (the factor of borrowed principal to yearly funds pledged) is 18 to 1 for 30-year bonds. This means that, as soon as the CITT gets back its full power to use funds it receives, it can sell bonds amounting to no less than $1.8 billion.

Note that $1.8 billion is not only half of the total capital cost of the entire, five-corridor SMART Plan, but is also more than the combined capital cost of the North and South corridors, which the County Commission has repeatedly said are our two priorities.

And we’re not counting on state or federal funds, or on MDX funds (which the County Commission had said would fund the east-west connector), or return of our auto tag renewals generated in our county ($167 million a year) or other existing sources like the more than $1 billion the state spends each year on roads.

So, who says we don’t have the money for rail?

Xavier Suarez represents District 7 on the Miami-Dade County Commission.