Another predictable success would be converting entirety of NYC into a driverless car zone, but we are probably not ready for the repercussions as a society
Maybe, or maybe just have more street cars and trams and such. More walking, and more biking to go from A -> B.
I'm not sure in the case of Manhattan that driverless cars are particularly valuable, and it's very much debatable whether they would be a predictable success for a few reasons.
Inevitably you arrive at a scenario where you have a limited number of them because of course otherwise would be to defeat the purpose of the congestion zone, and then you'll only have certain operators with the right permits able to extract money from moving people. Kind of like the taxi medallion scheme all over again.
One of the best things America could do is to be to reduce reliance and spend on cars. This applies to New York but even moreso to the rest of the country.
Already 90-95% get around without a car and the rest are paying. Car traffic is necessary to an extent. Compare how shipping companies offer Next Day Early AM shipping for 10x the cost of 4 day shipping. Hardly anyone uses it, but when you need it, you are glad to have that expensive option.
The future of nyc is one with electric kei cars puttering around for the one offs and trams and subways for everything else. I can see it in my minds eye and it is better in every way
Entirety seems a little extreme. Maybe gradually they could get there as society and technology changes. But yes changing large areas to pedestrian-only seems totally doable to me in NYC.