There is a certain amount of scammers in any and every industry and the world of taxis is . not an exception. However, a taxi driver taking the risk of cheating a rider of their cash is going to make sure you are an easy target before trying anything.
Essentially when booking a cab you need to make sure you ride with a reputable company and not a random car off the street. It helps to find a website and book online, getting a flat rate in advance. Shady characters will not likely have an online booking system.
Then for convenience and to be on the safe side, we also advise to keep exact change for the ride. Finally, it helps to keep your phone GPS out and monitor the trip as you ride