I wonder myself this too. Would people have to say "If NYC was a country would its GDP be 11th largest in the world compared to being the 12th largest GDP in the world like in 2024?"
What we can quantify is the economic impact the San Antonio River Walk has or the impact the Atlanta Beltline has which is billions of dollars in added economic activity. Based on those examples, likely it will increase the NYC GDP by millions if not hundreds of millions. We can prove with dollar amounts getting rid of cars in these cases increase the GDP by billions but in NYC they are only decreasing them so probably won't have the positive impact completely getting rid of cars does.
What we can quantify is the economic impact the San Antonio River Walk has or the impact the Atlanta Beltline has which is billions of dollars in added economic activity. Based on those examples, likely it will increase the NYC GDP by millions if not hundreds of millions. We can prove with dollar amounts getting rid of cars in these cases increase the GDP by billions but in NYC they are only decreasing them so probably won't have the positive impact completely getting rid of cars does.