For the first time in the world, a government has imposed restrictions on buying diesel vehicles for commercial use as an anti-pollution measure. Quite predictably, this move has come from the South Coast Air Quality Management District (SCAQMD), California, which leads the world in air quality management. It adopted three regulations on June 16, 2000, which puts a question mark on the future of diesel technology. The regulations bring into force a shift in the region's transit buses, garbage trucks and other vehicles like passenger cars used for commercial purposes from diesel to clean fuels.

From July 1, 2001, if public fleet operators owning 15 or more vehicles want to purchase new vehicles or replace any in their fleet, they must do so with alternative-fuel vehicles or equivalent low-emitting gasoline vehicles.The regulations define alternative fuel vehicles as any vehicle that is not run on diesel or gasoline and run on compressed or liquefied natural gas, propane, methanol, electricity or fuel cells.

The decision follows a study by AQMD in 1999 which showed that diesel exhaust is responsible for around 70 per cent of the total cancer risk due to air pollution in the area. "For more than half a century, Southern California's businesses and industries have reduced their emissions with cutting-edge technology to become the cleanest in the world. Now it is time for vehicle fleets - especially highly polluting diesel trucks and buses - to do their fare share in reducing smog-forming and toxic air pollution," said William Burke, SCAQMD's governing board chairperson.