TUCSON, Ariz. – Bright yellow taxicabs have become an icon of American life. But now pedestrians can hail cabs that are green on the outside and under the hood as more and more companies make the move from traditional cabs to hybrid cabs.

Cab companies all over the country have taken initiatives that are more environmentally friendly, adding hybrids to their fleet and converting traditional cabs to run on natural gas.

Taxicab Facts Cab drivers pay for their own gas Drivers lease each vehicle at a different rate Lease rates vary from weekly to 8, 12 and 24 hours. Priuses can only be leased for 12 hours Cab drivers are contracted independently

Discount Cab Company, based in Phoenix with service in Arizona, including Tucson, introduced 20 Toyota Prius cabs on Earth Day 2008 as part of its green initiative, "Green Cabs for Blue Skies."

“We are on a marching campaign to get as many Priuses as we can on our fleet,” said Jay Crete, fleet manager for Total Transit Inc., the parent company of Discount Cab.

The current number of Prius cabs on Discount’s fleet is above 80 out of 510 vehicles, making up nearly 20 percent of the company’s fleet.

“We’re trying to make 100 before the end of June and 200 by the end of the year,” Crete said.

According to a Discount press release, each hybrid cab will save 4,000 gallons of fuel per year, totaling 800,000 gallons of fuel per year for the entire hybrid line.

Discount Cab's green fleet in Tucson consists of three Prius cabs and one Ford Escape hybrid.

Crete said the company might add more Priuses if road maintenance in Tucson improves.

Discount Cab is the only company in Tucson offering hybrids, but other companies have also taken steps to go green.

The manager of Allstate Cab Company, a Tucson based company, said the company is making an effort to be more environmentally friendly.

“We have no plans of switching to hybrid, but we do have some vehicles converted to run on CNG (compressed natural gas),” said Al Moya.

Of the 300 cars in Allstate’s fleet, 58 run on natural gas, Moya said.

Toyota Prius Base Price: $22,00 Average MPG: 48 city/45 highway

Ford Crown Victoria Base Price: $24,600 Average MPG: 18 city/ 25 highway

Other cities across the country have also taken initiatives to reduce their carbon footprint.

On March 26, the New York City Taxi and Limousine Commission Board of Commissioners approved a "clear-air incentive program" for cab companies in an effort to boost the use of fuel-efficient and environmentally friendly cabs, according to the commissioner’s Web site.

The program offers cab company owners an incentive to encourage them to buy more fuel-efficient vehicles.