Feb. 28, 2008 - New York Mayor Michael Bloomberg has ordered the city's Taxi and Limousine Commission (TLC) to boost fuel efficiency standards for its 10,000-vehicle fleet of "black cars" servicing corporate clients. The new standards effectively force a switch to hybrid engine technology.

Black car emissions currently make up a surprising 2% of the New York’s total transportation-related emissions, as the vehicles typically idle in front of office buildings awaiting corporate customers. Hybrid cars switch to battery power when idling, reducing emissions of greenhouse gases and other pollutants. The new fuel-efficiency standards are expected to cut black car emissions by half.

In December, TLC approved regulations that will require all yellow taxis licensed after October 1, 2008, to meet similar fuel-efficiency standards.