I think an issue with this kind of policy (not necessarily in Manhattan) but in other cities is that often there is no alternative other than to drive to the city.
For example, my partner needs radiation for her cancer and the hospital is located in the city. There is no other option than to drive. I feel like this type of policy negatively affects people in this situation, with no other alternative.
A $9 congestion charge is probably a huge help to you. For just $9 per visit, you get much lower traffic and easier parking. Your very high priority trip is easier because lots of lower priority trips either didn't happen, or used transit instead.
Not if you're poor. $9 daily would be quite a lot for poor people, especially since radiation is daily. Furthermore you often have no choice but to use paid hospital parking due to mobility issues, as opposed to cheaper parking near the hospital.
I think this policy is only feasible in cities with decent public transportation. I’d struggle to list any more than 1-2 other American cities where this could be done though.
A lot of cities that do have public transportation seem to have extremely frustrating (i.e. multiple transfers) gaps if you aren’t using the system to-and-from work.
It’s also only feasible if actions like this congestion charge are taken to tilt the scales. Most people would not use public transit if they could avoid it. When there is enough road infrastructure to match the density, private transit is preferred because you can drive directly to your destination, not have public safety issues like on the subway, haul cargo, and do it all quickly. The only way to make public transit attractive is to artificially and maliciously mismanage things to make driving cars slow and expensive. Which frankly is hostile towards people.
For example, my partner needs radiation for her cancer and the hospital is located in the city. There is no other option than to drive. I feel like this type of policy negatively affects people in this situation, with no other alternative.