NEW YORK — Smoking is now illegal in all limousines, black cars, taxicabs, commuter vans and paratransit vehicles licensed by the New York City Taxi & Limousine Commission.

While the number of companies that officially or unofficially allow smoking in their vehicles has dwindled dramatically over the past few years, the new law is still expected to affect a large number of business owners, clients and particularly drivers, who typically spend long hours in their vehicles waiting for clients.

The ban will be enforced by local law enforcement agencies through “direct observation” or the “consumer complaint process,” said TLC Commissioner Matthew Daus, adding that the TLC’s enforcement jurisdiction does not extend to passenger behavior.

According to the Smoke-Free Air Act, passengers who smoke in TLC-licensed vehicles are in violation of the law and may be subject to a civil penalty of $100 for each violation.

Chauffeurs are prohibited from smoking in vehicles “irrespective of whether the vehicle is occupied by a passenger,” according to the TLC. Drivers are subject to a civil penalty of not less than $200 for each violation. Operators may be subject to additional penalties for the misdeeds of employees who smoke in their vehicles, the TLC added.