If you've ever admired the words "powered by clean natural gas" on the back on a city bus as it powered by you, you've been witness to the results of an innovative government program to stimulate use in alternative fuels.  Through collaborative public-private partnerships, the Clean Cities program works to increase the nation's economic, environmental and energy security by reducing petroleum consumption in the transportation sector.

Organized and sponsored by the Department of Energy's Vehicle Technology Program, the Clean Cities program, composed of 90 U.S. cities, displaced over 375 million gallons of gasoline last year, and nearly 1.6 billion gallons of gasoline since its inception in 1993. 

To give some perspective, the U.S. consumes about 400 million gallons of gasoline every day.  Looking at these numbers, one might conclude that in 15 years of existence, the Clean Cities program has only displaced 4 days worth of gasoline consumption.  While correct, the assessment doesn't provide an accurate portrayal of the program's effectiveness.

The Clean Cities program mostly targets cities and public transportation in cities.   The goal of this small program isn't to convert the whole country to alternative fuels; it's to wean urban transportation fleets off gasoline.  So while the entire country -- particularly those outside of cities -- burns through fuel at unbelievable rates, urban transportation fleets use only a fraction of the total gasoline consumption.  Moreover, the program's progress is increasing every year, as depicted in the chart below.

Clean Cities works by offering information to public and private stakeholders about the benefits and costs of going green though databases and forums.  Essentially, the program brings disparate groups together in an effort to promote public-private partnerships that are beneficial to all parties. In doing so, they promote the use of alternative fuels like natural gas, biodiesel, ethanol, propane, and electricity.  

Small grants are also provided to stimulate interest in alternative fuels and energy-efficiency technologies to stimulate interest further.  Grant issuances vary year to year, but average between $20-40 million per year in total. 

The Clean Cities coalitions are on track to reach 3.2 billion gallons of gasoline displaced in 2020. Coalitions have steadily increased the number of alternative fuel vehicles (AFVs) on U.S. highways, with gains averaging around 15% in recent years as depicted in the chart below.

Other highlights of the program include the following:

• Seventy-one percent of the 2006 gasoline displacement came from the use of alternative fuels. Thirty percent of that was from the use of compressed natural gas, mostly in heavy-duty vehicles.
• The use of E85, a blend of 85 percent ethanol and 15 percent gasoline, grew substantially in 2006, largely because the number of E85 stations doubled – from 436 to 995 – in the year. E85 accounted for 24 percent of gasoline displacement from alternate fuels in 2006.
• Coalitions reported acquiring almost 44,000 hybrid electric vehicles in 2006, a 61 percent increase over the 17,100 HEVs purchased in 2005. HEV use accounted for the displacement of approximately 9 million gallons of gasoline.
• Idle reduction efforts displaced 8.4 million gallons in 2006, including 1.2 million gallons from truck stop electrification.
• Almost 2 million gallons were saved by reducing the number of miles traveled.