[kemitche]

I don't see suburban areas ever becoming truly mass transit viable.

I DO see a future where the benefits of living in denser-packed cities outpace the downsides, encouraging more and more of the US population to live in areas that are (or become) population dense enough for car-free lifestyles to be viable.

[fyfy18]

There are plenty of parts of London (typically zone 3 and out) which is full of low rise single family homes. The transit links in most of these areas are good enough that you can easily get by without a car (even as a family, although of course it would be easier by car). At least by my definition these would be a "suburban area".