Does everyone pay?

State legislators are considering several possible exemptions for drivers who are low income, have disabilities or are going to medical appointments. Assemblyman David I. Weprin, a Democrat from Queens and a leading opponent of congestion pricing, has called for an exemption for all city residents, which seems unlikely.

Though details are being worked out, fees are expected to apply to people driving into the congestion zone from elsewhere in the city, including parts of Manhattan north of 60th Street and other boroughs, as well as beyond.

Drivers who live in the congestion zone would not pay when they drive within the zone or when they leave the zone, but they will when they return from elsewhere.

Of course, that could change if an exemption or discount is granted to residents of the congestion zone. For instance, London offers a 90 percent discount for registered residents of its congestion zone.

But more exemptions could mean higher tolls for everyone else.

After all, the fees are supposed to generate $1 billion a year. “Every exemption you provide is less revenue coming into the system,” said Kate Slevin, a senior vice president for the Regional Plan Association, a research and advocacy group that supports congestion pricing.

Alex Matthiessen, the head of a grass-roots campaign to support congestion pricing, said too many exemptions could hollow out the plan, making it ineffective. “Now we must guard against a race to the bottom as legislators seek carve-outs and exemptions for every class of driver.”

Instead, he suggested taking other measures, such as offering discounts on commuter railroads for city residents and subsidizing ride-app services like Uber for those with disabilities, to ensure more people benefit from congestion pricing.