Climate change. Rising fuel prices. Traffic deaths. Pollution. Road maintenance. The obesity epidemic. Industry bailouts. Terrorism. These are the formerly hidden incalculably massive costs WE ALL pay to subsidize the automobile era, whether car owner or not.
I'm not here to tell you that bikes are the answer, that they can merrily solve these problems, and to recommend that the sedentary suddenly change...
I'm here to tell you with absolute certainty that a large scale shift off of cars planet-wide

One can debate how difficult cultural trend forecasting is. Yes there are unknown unknowns, but to ignore trends and data of the scale we're seeing would just be foolish. Identifying this, I consider it a duty to help ease mine and others' not just readiness for, but enjoyment of this journey through transitional times.

Visions of smart travel pods, free power and teleports are fun and may happen some century. Contemporary future-looking transportation designs like solar cars and ultra lights are useful research but have costs as well. Bio-fuel is a negative distraction. Hydrogen and other storage media solutions are beautiful, but secondary here to power acquisition and conversion. In the near term I guarantee that practical reality will have its way. The inevitable solutions to clean, safe, efficient, inexpensive, reliable, widespread on demand travel are simple, obvious solutions; not cars.

The automobile era, and by extension much heavy industry, are historically destined to be a massively important but finite period. When Henry Ford simply followed business logic to change an impossible luxury into a commodity, it was a different world. Resources and air were effectively infinite. But an arms race of sorts has given the monster a life of its own, and it feeds on what margin of irresponsibility we allow. For cars to exist as-is requires an enabling balance giving low price per mile. Fuel must be cheap and plentiful, and other costs low (or hidden). The passing of peak oil (varying estimates place the exact recent year of that) means that the oil energy value equation that fueled our species for over a century will right now begin changing. Inevitably, as extraction costs increase, oil WILL become a niche product in the distant future, or applied more appropriately to food and plastics where it is less replaceable. As true lifetime and ongoing costs effect the market, the automobile WILL become a luxury and specialty product. Where will that leave more and more drivers? On feet and bikes, or happily at home just a little more often.

Cars WILL gradually become a thing of the past for a suite of powerful reasons.
Not even counting current transient issues such as bailouts, import imbalance, the recession, and this oil tainted war... the persistent long term negatives of cars are too awful to tolerate any longer. These include:
Deaths, by accidents and pollution.
Environmental costs, gradually becoming widely recognized.
Societal costs, such as subsidized infrastructure.
Total ownership costs, increasing and finally sinking in.
Fuel cost, and all that procuring and securing oil entails.
And decreased quality of life, such as obesity and cardio/pulmonary illness.

These are not distant clouds or academic concepts; these are exploding issues. We are at a germinal point in the process of growing out of cars right now. Precipitated by a dramatic increase in car use over just the past few decades, and the passing of peak oil.

Now in case I sound overly dramatic, be aware I consider myself one of the most sane and balanced people you'll ever run across, though some ex girlfriends would dispute it. I acknowledge that moving off of cars will have massive ripples throughout society on a scale that's hard to imagine, but likely I assure you nonetheless. The future is not just bikes, but walking, skating, transit, not going anywhere (such as telecommuting), and possibly most of all, greatly changed expectations. Personally I like the idea, and see it as a healthy correction to a former imbalance; or a market over-valuation adjustment in capitalist terms.
But regardless of how sick I personally feel car culture is, I didn't choose this future. I'm simply reporting what predictably will be.
Frankly, I see a large scale conversion off of cars to be a best case scenario requiring some help, and I challenge anyone to show me a well reasoned cheerier alternate view. If we do not say no to cars, I fear the other path is darkness, though to some a future WITHOUT cars is the dystopian hell to be feared.

Now for numbers fans, I'll present some supporting data. Sadly I recently heard that an outrageous percentage of Americans do not know or do not believe that the Earth orbits the sun, much less in climate change. But if I reach just one person... well then I've failed miserably.