To head off the almost inevitable recapitulation of yesterday's parade of misinformed complaints by teenage libertarians, please actually read the paper before commenting. The paper shows there was no significant reduction in entries to the congestion charge zone by cars, vans, and light trucks. And you can confirm this conclusion is consistent with their source data using their github repo. The reduction in pollution is coming from the significant decline in heavy truck traffic. Truckers were using lower manhattan as a cut-through route to other places and they are now doing that less, exactly as congestion pricing planners long argued.