The City of Houston has taken steps in the right direction to improve the city's air quality and reduce fuel consumption. The city began this venture with the purchase of five Toyota Prius hybrids integreated into the city's Planning and Development Department's fleet as a six month pilot program. After being monitored for their performance and fuel consumption the city has since expanded its fleet of Toyota Prius's well into the hundreds.

This pilot program began under former Mayor Lee Brown who states "By incorportating these alternative fuel vehicles into our fleet, it is our hope that our actions encourage similar participation by Houston-area residents as well as the corporate community." Our current Mayor Bill White, who himself drives a prius advocates, that the hybrids will actually save the city money. "Over the five years, we'd like to convert at least fifty percent of the city's fleet, which would mean well over a thousand vehicles. We want to do it as fast as possible when vehicles are due to come out of service," says White.

Fuel mileage is directly related and proportionate to NOx pollution. The use of hybrid vehicles in Houston has been ideal because it allows for the reduction of NOx in inner city driving where it is most important.