Authorities in the Mexican capital, one of the world's most polluted cities, have launched a new low-cost transportation service with an eye toward encouraging mobility alternatives and reducing air pollution.

For a fee of 90 pesos ($6.40) per hour, people can now rent a car and then drop it off at special locations, a program that has already been implemented in cities in Germany, Switzerland, Canada, the United States, Costa Rica and Brazil, Mexico City Mayor Marcelo Ebrard said.

The Carrot Shared Automobile System is being started up with 20 fuel-efficient gasoline-powered autos and has 16 car-return locations.

In this way, "the number of vehicles in the city is being reduced and the entry of new autos is being avoided," said the director of the Carrot company, Diego Solorzano, at the presentation of the new program.

To use the new service, he said, one must pay 300 pesos ($21) to obtain a user card and have both a drivers license and proof of residence.

The rental cars get 13.9 kilometers per liter of gas (about 34 miles per gallon) and have an efficiency level on a par with hybrid vehicles. "They are very recommendable from the point of view of gas consumption," said Martha Delgado, the municipal environmental secretary, at the event.

The firm forecasts that the new service will motivate 15-30 percent of car owners to sell them, and it could result in up to 60 percent of motorists putting off buying a new vehicle.

According to calculations by capital authorities, automobiles are standing parked for 80 percent of their useful life, given that the majority of people use them simply to get back and forth to work. However, these few hours of use bring with them maintenance, fuel and parking costs.

With this alternative car rental program, authorities are seeking to eventually remove 40,000 vehicles from circulation.

The initiative is designed to reduce traffic and pollution in Mexico City and rekindle confidence in other transport options like public services and Ecobicis, a bicycle rental program that has been in operation since 2010.

The metropolitan area, with almost 19 million residents and more than 5.5 million vehicles, is one of the world's most populated areas and has very high levels of air pollution.

Although pollution levels have been reduced compared to what they were in the 1990s, Mexico City is covered with a perennial blanket of smog and accounts for 9.1 percent of the country's carbon emissions. EFE