Description:
The source of the data is the following: US Department of Energy's Annual Energy Review Interactive Data Query System found at http://www.energy.gov/transportation/index.html. The data query system defines alternative fuels as ethanol (85% or 95%), electricity, petroleum gases (liquefied), natural gases (liquefied or compressed), and methanol. The data base also gives the total amount of fuel consumed by these vehicles in total, and by individual type.
The data show a decent linear trend in the number of alternative fueled vehicles (AFV's) in use. After fitting a linear function to the data, we might forecast somewhat and predict the number of these vehicles to be in use in future years. Obviously forecasting too far into the future has its dangers as new technology and consumer attitudes often do not track linearly.
In the year 2000, the US was introduced to the electric-gas hybrid automobile. Models include the Honda Insight, the Toyota Prius, and the Ford Prodigy. The manufacturers of these models claim their vehicles get up to 70 mpg. It will be interesting to see how much the AFV trend increases from 1999 and 2000.
