By 2020 we should expect some major changes to the family car, which will result in quite a paradigm shift.
One change we can already see coming is the advent of the fully electric car. By 2020 we can expect that the majority of NEW cars will be fully electric as advances in battery, computer and electric motor technology revolutionize this aspect of the auto.
But that's NOT the really big change. After all, the electric car looks and feels pretty much the same as a gasoline powered vehicle, and will be marketed and sold in a similar manner.
What will be truly new will be the robot car. The technology already exists today for a vehicle to drive across the country and on urban roads without a human driver, and it has advanced rapidly in recent years. By roughly 2015 we should be seeing some prototype models of cars capable of driving themselves, and by the end of the decade there should be a few higher end models available for mass purchase.
So what's the big appeal of having a robo-car? Well, over time--in the next decade (the '20's) robo-cars should revolutionize the way we relate to the automobile. Today, there is tremendous waste because people purchase cars for their own use, then have them sit unused for about 90% (or more) of the day.
Suppose, instead, that you belonged to a collective that owned a variety of shapes and sizes of robo-cars (similar to today's car-sharing operations, like Zip-car) that would pick you up at your doorstep when you wanted, and then drop you off at the entrance of wherever you're going, and then go park itself on a remote lot until the next collective member needed it. The result would be fewer vehicles on the roads and less need for buildings to maintain expensive parking facilities. (And for homes to have wasteful 3-car garages.)
Further, you'd be picked up by the type of car you need at the moment. Many American families have a huge SUV for those relatively rare occasions when they go on a family trip, or take a gang of kids to a soccer game. Imagine if your subdivision instead was served by a collective that had a handful of SUV's for when you need them, but otherwise would send you on your work commute in a two-seater (or one-seater for that matter).
The robo-cars would be quite "smart"--they would know where you're going and be sure to be charged with enough juice to make it; they would schedule time to re-charge themselves between assignments, in off-peak driving hours.
Another benefit of robo-cars--down the road, when there are sufficient numbers--would be the ability to take them on restricted highways limited solely to robo-cars, where they could go much faster than human driven cars, because they'd all be communicating with each other and with various traffic signals. Traffic jams could be avoided because the robo's would be able to see much further ahead and adjust speeds accordingly. Indeed, in urban areas, traffic signals might be avoided altogether as robo-cars communicating with each other would adjust speeds to navigate intersections without colliding.
Of course, the biggest benefit of robo-cars is eliminating that nemesis we all face on today's roadways: the OTHER driver, that idiot who is going too fast, or too slow, or not paying attention, or not signalling, or cutting us off, or trying to cut in line. (Of course, we ourselves NEVER do these things--only other drivers.)
And what will humans do while being transported in their robo-cars? Why, they'll be doing the 2020's equivalent of texting (and maybe drinking a beer, to boot).