It is time to consider the possibility that the New York State Thruway Authority has outlived its usefulness. No, make that the likelihood. At this point, the presumption should be that it serves no valid purpose, and let defenders make the case for its continued existence.

Good luck to them.

Start with the minimum: In its current configuration, the authority doesn’t know what it’s doing. Its chairman, appointed by Gov. Andrew M. Cuomo, is developer Howard Milstein, a wealthy man who seems to know as little about highways as he does about developing the property he controls in Niagara Falls.

Consider: Over the past several months, the authority insisted that it was going to raise tolls on trucks by a staggering 45 percent. Then it didn’t. It held secret meetings. Its vice chairwoman blasted the authority for its lack of transparency.

Last week, after Cuomo belatedly criticized the toll hike, the authority announced that it was looking at all alternatives to the 45 percent increase in tolls, including a broader increase that included cars.

Oops. A day later, it backed away from that announcement with another announcement, which said that option won’t be considered. At least, not until the next announcement.

If the Thruway Authority were a driver, it would have lost its license by now.

The evidence of mismanagement has been obvious from the moment the authority said it wanted to raise tolls on trucks by 45 percent. That’s a destabilizing increase that betrays poor oversight of the authority’s finances.

The cost of a Big Mac doesn’t suddenly go up by 45 percent. The cost of a movie ticket doesn’t jump 45 percent overnight. Those costs must remain reasonable because of competition, and the urgent incentive not to drive your clients away. Thus, private-sector businesses control their expenses, raise prices reluctantly and try very hard not to infuriate their customers. If they do, it’s because of a crisis, usually within the ranks of management.

State Comptroller Thomas P. DiNapoli has long said that a toll hike should be a last resort.

He wants the authority to first find savings by improving management of the system, including eliminating vacant positions, reducing overtime and marketing unused property for sale or lease. His auditors also showed that more could be done to collect millions of dollars in E-ZPass tolls and fees that go unpaid. Raising tolls, he says, is the easy way out for the authority because it relieves pressure to make the necessary changes.

A public authority is not a private-sector business, but certain business practices need to be followed if its rate-payers – in this case, the drivers who pay the tolls – are going to be given fair value for their dollars. Plainly, the Thruway Authority has not done that.

It has insisted that the toll increase for trucks is needed and that tolls would still be lower than in other states. But that evades the point of responsible stewardship. The very point of a public authority is that it can focus exclusively on the task for which it was created, in this case, building and maintaining an extensive system of highways and bridges in a fiscally responsible way. It can bring its expertise to bear and provide a necessary service.

If the Thruway Authority can’t do that, what is the point of its continued existence? Other states get along without a highway authority alongside its own transportation department. It’s time for New York to think about going that route.