I'm not here to give alternative solutions, I'm here to tell you the current solution is slightly worse than nothing.
You would have to make the solution fairly complex for it to be beneficial. But I'd start with quantifying why people are in the city, rather than treating them all the same.
If it were my job, I'd have a better solution than congestion charges, that's for damn sure.
>"convert an urban highway into a beautiful linear park and waterway"
They converted an inner urban highway and other highways in the sky (in the immediate city centre) to walking paths while adding extra highways to the pool further out from the city centre. Removing the inner highways added to congestion, adding the outer highways reduced congestion.
They did not add congestion charges and the city handles it fine. They are not stupid like a lot of people here are.
You may or may not be stupid. I don't know.
Do you have anything to reply? I think you're running afoul of guidelines too.