The idea translates easily into any language: Charge drivers for using congested streets and watch them change their habits. It has become an increasingly attractive tool for major metropolises overwhelmed by the traffic strangling their streets.

But actually carrying out congestion pricing has been anything but easy — at least in three cities that are often cited as international models. In London, Singapore and Stockholm the fees were met with skepticism and outrage by commuters and civic and business leaders, though they later proved effective in reducing traffic, congestion and air pollution.

As New York debates whether to join these cities after decades of stalled efforts, their experiences could provide a road map. Each city does congestion pricing in its own way. Singapore sets varying fees based on the road and time of day, and adjusts them in response to traffic conditions, with fees going up when there is congestion, and down when there is not. Stockholm also sets varying fees for a congestion zone covering the central city area, with the highest fees at the busiest times of day. But its system is less flexible than Singapore’s since those fees do not regularly fluctuate with traffic and any changes require the approval of Sweden’s Parliament.

In contrast, London charges a simple flat-rate of $16 per day no matter how often a vehicle goes in and out of a designated congestion zone in the center of the city. In New York, a state task force has proposed a flat rate of $11.52 per day for passenger cars — and $25.34 for trucks — for entering a congestion zone in Manhattan that would stretch from 60th Street south to the Battery. Taxis and ride-hailing cars could face a separate charge of $2 to $5 per ride.