You shouldn’t have trouble finding a taxi in Cancun, about every third vehicle seems to be a taxi.
To flag a taxi you don’t need to do more than just look like you want one! A little wave or standing aimlessly at the side of the road is usually enough for a driver to stop.
The golden rule is to always negotiate your price before you start your trip. If you can’t agree a price then find another taxi or take the bus.
Prices will vary, obviously on how far you want to travel, but also prices will be more expensive late at night/early morning when there are a lot of customers about, you may also find that the prices are hiked if you are drunk, but then again you probably won’t remember!
Safety is not high on the agenda of taxi drivers and you will often find seatbelts not fitted or defective, especially in the rear seats. Driving can be described as lively at best, reckless at worst.
Maximum occupancy is 4 passengers and this is something that is fairly strictly enforced, although not always. Try to avoid the taxis that park directly outside the hotels, clubs and restaurants as these will charge a higher price. Just walk a hundred yards down the street and put your arm in the air, you’ll normally have a taxi pull up within seconds.
The driver will normally set the price so it includes a little tip for him so it’s not really necessary to tip extra unless he performs an extra service such as helping with bags, multiple drop offs etc, but an extra 5 or 10 pesos is a nice thing to do.
The price for locals anywhere in downtown to anywhere else downtown is 28 pesos flat rate. So if you have to travel somewhere downtown I would suggest catching the bus to Ave. Tulum and then flagging a local cab for the cheapest overall price (and the reverse for your return).
Don’t be surprised or alarmed if the driver also picks up someone else to share the ride though, that’s quite normal downtown.