Monday marked the first weekday that thousands of drivers in New York paid congestion price fees when entering parts of Manhattan. Passenger vehicles will now pay as much as $9 to drive past 60th Street during peak hours.

The toll, known as congestion pricing, is meant to reduce traffic gridlock in densely packed Manhattan while also raising money to help fix the city’s ailing public transit infrastructure. It formally took effect Sunday.

The program is the target of several lawsuits and of President-elect Donald J. Trump, who said he will end it permanently once he takes office on Jan. 20.