If you think that money from tolls is actually going to go to buses and improved public transit and not just into some Bel-Air businessman's brother's pocket, I have a bridge to sell you in Brooklyn.
I know things are done differently in America, but the profit from London's congestion charge is invested in public transport by law. For at least the first few years, it was entirely spent on improvements to buses -- giving much more capacity, and faster journeys due to the reduced congestion.
* Schedule 23 of the Greater London Authority Act 1999, to be precise, but the whole act is a 500 page PDF, so my curiosity ended there: http://www.legislation.gov.uk/ukpga/1999/29/pdfs/ukpga_19990...
This is also true here, but someone has to build or design those improvements to buses. The contract will typically go to someone's brother's shell company or something, especially in California. The approach to the Golden Gate Bridge cost a million dollars per foot of road. Yes, seismic this-and-that, environmental reports, noise studies, etc, but the corruption is just rampant in Cali.
Won't happen in the EU. It's forbidden for any public entity to give a contract such as this one without tendering it. Certainly not a perfect system, but it counteracts corruption pretty well.
That's why a good toll system should fund the public transit. The higher you set the tolls, the more buses you can offer to those who find it too expensive.