According to a new report by expense-management system provider Certify, 47% of the ground transportation rides in March were through Uber.

The transportation rides tripled from the 14% of rides that Uber had just over a year ago in January 2014. Uber now tops taxi rides for business travelers in few cities. Certify based its findings on receipts submitted by North American clients each year.

In its hometown of San Francisco, 71% of rides during the first quarter were for Uber, 29% used taxis. Uber also beat out all other forms of ground transportation in Dallas, accounting for 56% of the rides.

Certify CEO Bob Neveu said, "While we often see noteworthy market shift, leading restaurant chains and hotels exchanging leadership positions, for example, it is unprecedented to see one vendor grow to take such a commanding market share within one year's time".

Although, taxis, limousines and airport shuttles still dominate the ground transportation business, Certify's report indicated that ride-hailing services are on the rise among business travelers.

Uber connects travelers with various cars through its smartphone app. Some drivers work for car-service companies; others spend a few hours driving their personal cars on the side for some extra money.

Although business travelers might be quickly moving towards Uber, there are major concerns by their employers. According to Mike McCormick, executive director of the Global Business Travel Association, many companies are worried about issues of safety and liability.

Uber drivers aren't regulated by government taxi licensing authorities. The company has faced criticism for accessing customer data by its employees inappropriately. The company does not properly screen drivers and hardly makes sure that they have clean criminal records.