It is very hard to build new gas docking terminal (NIMBYism and BANANA stuff)

BANANA is Build Absolutely Nothing Awfull Near Anyone.

If you take ALL the natural gas that was used (in 2005) for electrical production and used it in place of gasoline, you would displace only 37.5% of all the gasoline used.  Furthermore, I drive a NG car periodically.  They burn NG or gasoline but not "both" so when you run out of NG (actually when the regulator cuts you off), unless you have some way to quick-connect a pressurized bottle of NG, you are stuck.  

Our Hondas have a maximum fill pressure of 3200 psig.  Our other larger vehicles have tanks pressures up to 3600 psig.  Filling them is relatively simple with the quick connect system, but it is not fast.  A near empty tank can take 20-40 minutes to fill to capacity with a large "fast" compressor station.  Since you are compressing gas from a much lower "street pressure" to a much higher tank pressure, the compression causes the gas to heat.  These compressors have a very large intercooler to drop the temperature back down to acceptable levels prior to filling the vehicle tank.  Nonetheless, these tanks do get quite warm when filling.  A "slow fill" system or systems with small intercoolers may take as long as eight hours to refill.  Changes the experience of filling the tank to a "career."  

Add to that the fact that electrical generation using natural gas primarily uses relatively new, high-efficiency simple cycle or combined cycle turbines that can only burn natural gas or distillate oil.  So whatever  gas you take away  (and oil you save from automobiles) has to be made up by more oil use.  These new simple-cycle CTs are much more efficient that just about any coal-plant except supercritical, double reheat EGUs with a nice cool lake for condenser water.  And there aren't any coal-fired power plants that can match the current generation combined cycle CTs.  

That's the principle behind IGCC...to gasify coal into a product that can be burned in a high-efficiency combined cycle CT that is more efficient than an equivalent coal-burner.  You give up a substantial amount of the efficiency by using the coal's heating value to gasify it, but the operating at a net 40-45% efficiency compared to the more nominal 30-35% efficiency of a standard coal-plant may be worth the difference.

But the underlying point is that with 2% annual growth in various energy demands AND the need to change to a different distribution of fuels...well it's just not going to happen.  Consider that without PO staring us in the face and we kept everything in it's current proportions (oil, gas, coal) that in 35 years we have to have the ability (and the infrastructure) to handle twice as much of EVERYTHING as we do now.  

More over, the substitution of coal (or more clearly the liquifaction and gasification of coal) for other products we currently use won't be as much help as many think.  
Thirty years ago, "we had" about 400 years of coal at the usage rate of the mid-1970s.  Today we have between 250-275 years.  Did we really use 125-150 years of coal in 35 years?  Yes, mostly because we've doubled our rate of consumption and our estimates of the reserves (and their declining quality) have become more refined.  

Currently, coal accounts for about 23% of our total energy use.  With the combination of "normal growth" and susbstitution of coal products are we really likely to have enough coal for "hundreds of years?"  Probably not.  

At the end of the day, it will be easier and cheaper to convert one's F-150 to run on an EtOH blend with a smarter carb, then to try and change the entire motoring infrastructure.

And unlike the fossils, EtOH can be produced anywhere on the continent, from practically any carbonaceous material available.

Add conservation, electrification and other mitigation strategies to the mix and we should be able to keep up with a modest rate of decline.