A Wall of Resistance But the politics of congestion fees are far more problematic than the technology or economics.

New York's own flirtation with congestion fees offers little reason for optimism.

With gas well over $3 a gallon, many drivers complained that the congestion fees amounted to an assault on the middle class.

Mr. Livingstone said the congestion fee for drivers of vehicles that produced the lowest carbon emissions would be dropped.

For congestion fees to achieve their intended effects, they must be high enough to cause large numbers of people to alter their behavior.

It is already clear that concerns about the effect of congestion fees on poor motorists underlie much of the gathering opposition to the mayor's plan.

Initially this was planned as a congestion fee, not a tax.

But in the Death Star scenario, the congestion was entirely illusory and the congestion fees would therefore simply increase profits.

The mayor and his administration have said most people would have heard about the congestion fee, though some lawmakers say many would not.

Computers process the images, matching the license plates photographed against a database of drivers who have paid their congestion fees.