Most of the people in both Finland and Japan live in cities, while most North Americans live in cities. Moving away from cars in rural areas may not be easy, but there is no reason why it would not be possible in the cities. The things that are needed are: denser cities (less tight zoning laws) and more alternatives to driving, like bike lanes or trams. These things are achievable by policy change. Also, the USA has around five times as much population density across the country as Finland, so while it may be big, it is not too big for decent alternatives to driving