In William Halal's "Technology's Promise" the concern for a much improved global transportation system is an underpinning to continued, sustainable and ecologically friendly, economic growth. The advances in technology like, hydrogen fuel cells, hybrid gas/electric engines, and control automation do seem to offer some exciting prospects. These prospects do have real barriers, and the barriers must be considered.
For example the prediction that air transport may become as ubiquitous as car ownership; "A Plane in every driveway" as it were. But reality just says "no". There are tooooo many obstacles in the way of this one: economic, technical, legal, social, etc.
Consider air traffic control alone. Let's pretend that everyone is a good, curteous, and vigilant driver (ha,ha,ha,ha!!...oh!,My ribs!), can you imagine the size and complexity of the air traffic control system required to keep safety? this is assuming that some method of automatic air collision avoidance system existed? Even the Chinese couldn't afford that!.
No, this fellow was much closer with his prediction of a Moon base. Thats much more likely to happen --if-- there is a "Very" compelling value proposition behind it.
Then, we have Hydrogen fuel cells. Again, discounting the cost of the technology itself (significantly more expensive than a comparable 'hybrid' vehicle), you have the cost of infrastructure required to support the technology. Hydrogen does not occur naturally in sufficient quantities that it could just be collected. It has to be synthesized. Here entire new Hydrogen production, storage and delivery systems are needed. Hydrogen, as most folks know, is super volatile --much more so than gasoline. There is an entire development effort just in producing delivery systems that the average person can use (without blowing everyone up). The final note here, is that these predictions were expected to be in some sort of deliverable stage around 2010....its 2011 and were not much closer ubiquitous flight or hydrogen fuel cells than we were in 2005