Ride-hailing apps such as Uber are synonymous with cheap and efficient travel but there are still some cities in the world where it's cheaper to hail a traditional taxi.

If you're zipping around a new and unfamiliar city, you might assume that it's cheaper to get from A to B with an Uber. As the biggest ride-hailing app in the world, it offers competitive fares and a user-friendly app but it's not always the cheapest option.

In Riyadh, Saudi Arabia , for example, Uber is becoming increasingly popular and even has a special feature that lets female drivers select a preference for female-only riders. But opting for a taxi over an Uber in the Saudi capital is cheaper and will save you £3.22 ($4.15) per km. Elsewhere, in New York , it's cheaper to flag down a yellow cab by about £0.43 ($0.55) per km. And in Milan , taxis also cost less (£0.82/ $1.06 per km) than an Uber.

This is according to a report from Globehunters , who examined the cost per km of riding with Uber compared to hailing a taxi in 55 of the world's most visited cities to see where savings can be made by choosing one mode of transport over the other. It found that Lisbon , Porto , Madrid and Seoul are other big cities where it's cheaper to get a taxi.

However, only 11 cities were found to offer taxis cheaper than the ride-hailing service. In Athens and Istanbul, prices are the same. While in Cancun choosing Uber over a traditional taxi will save you £1.27 ($1.64) per km; in Amsterdam , £1.03 ($1.33) per km, in Munich ; £0.90 ($1.16); in Toronto £0.73 ($0.94); in Sydney £0.42 ($0.54) and in Los Angeles it's marginally cheaper at £0.35 ($0.45) per km.

In London it's also cheaper to hail an Uber, by about £0.99 ($1.28) per km; though a decision last month by the capital's transport authority to reject the ride-hailing firm's application to renew its licence has put its long-term prospects in doubt.

Want to see where more savings can be made when it comes to transport? See here for Globehunter's full list.