I fear that going to biofuels will not only jack the price of corn up, it will also encourage the use of more GM corn (which is already an issue). AND this still means using internal-combustion engines, which are so out-dated it isn't funny. Half the energy those thing produce is wasted in the compression phase, and much more as heat.

The first fuel cell was developed in 1839; they were in common use by NASA in the 1960's - and no one grabbed on to that because what? Lack of vision? I dunno. It's frustrating.
Hydrogen can be produced with solar, wind, and other passive power sources pretty much anywhere, sold for
less than the equivalent cost of gasoline, and then get far better mileage without wasting the power potential of the fuel AND producing far less pollution. (Including noise pollution - can you imagine how quiet a fuel-cell tractor-trailer would be? And running a fuel cell over-night just for heat or A/C would be so much nicer than running a 400 hp diesel for the same reason.)
Yes, there are still technical and safety hurdles, but not for long.
Big oil is already investing in hydrogen as fuel.So once we have that out of the way, and large fuel cell power plants, we can ethically go to the next step: MagLevs.
I want to
scream at the companies researching and producing these - their lack of imagination is astounding. They are all building the same thing that has been around since the first steam locomotive!
Screw that! Make that sucker fifteen meters wide and eight meters tall!

We aren't stuck at making everything two horses' asses wide anymore. Make the inter/transcontinental trains into moving malls - parking included, so you don't have to rent a car at your destination. Include suites, restaurants, libraries, sleeping tubes for the economy-class - the possibilities are just about endless.
And "overnight" package delivery would no longer require an airplane, with it's accompanying fossil-fuel use and pollutions.
Smaller, more "conventional" versions would still operate locally and regionally.
So it costs half a trillion dollars. Put the Mission to Mars off a year or two.
Better yet, I'll write a check.

But it's doable, and would create lots and lots of work all over the country for a good - and long-lasting - cause.
Infrastructure, price stability are two of the big issues.
You have to have the gas stations availiable to fuel hydrogen car while you have to have the hydrogen cars to warrent having gas stations. That's why natural gas started with fleet cars and trucks. A company could build it's own gas station for vehicles that came back to the lot every day. Expect to see it done in dense urban & suburban areas first for fleets followed by letting the general public use the fleet facilities.
You also have to have price stabilty. Gasoline has to remain expensive for a number of years before people will consider getting rid of existing vehicles and buying the new hydrogen ones. These people also have to think that they will be able to fill up anywhere, or that they are not going to travel with the vehicle.