Globalization of the world’s economy requires that humans and
their goods move long distances. Consequently, passenger and
freight travel are likely to double during the next half
century. This expanded travel derives both from human population
growth and from everyone traveling a greater distance each year.
In addition, more people possess their own light-duty vehicle
(passenger car or small truck) and are using them for travel.
Petroleum serves as the energy source for over 95% of
transportation. The transportation sector consumes half of the
world’s petroleum output, a proportion that is likely to
increase in the future. A straightforward strategy for
prolonging petroleum supplies is to invoke additional
conservation measures in the transportation sector. The Middle
East supplies most of the world’s petroleum and has the world’s
largest proved oil and natural gas reserves (i.e., reserves that
have a reasonable certainty of being extracted). For this
reason, among others, the political volatility of this re