Once you arrive in Cancun and you are tired of sitting at your hotel, there are a number of transport options for exploring the city.

Buses:

Run round the clock 10.5 pesos per ride.  American coins are not accepted and larger bills are hard for them to change. When you pay for your ride, you will be given a small paper ticket. Hang on to this, as many times there is a discount at local shops. If you miss one, don’t worry; another will be along within minutes. The buses that run in the hotel zone are mainly R1 and R2, either one will take you back and forth between downtown and the hotel zone. The quality of these buses range from older without air conditioning to new, air conditioned coaches with TVs and WiFi. 

Unsure of when to get off the bus?  When you board, if you let the driver know where you are heading, he will let you know when the bus arrives at your stop. Also note the stone markers found in the median denoting the KM number. An easy way to remember which side of the street to catch your bus: The ocean side of the street buses go north, towards downtown Cancun, and the lagoon side of the street go to the end of the hotel zone. 

There is an excellent website outlining all of the local Cancun bus routes:  http://cancun.rutadirecta.com/ They also offer an excellent app for IPhone and Android that includes A to B trip planning. 

Taxis:

One will not go more than a few minutes without seeing a taxi in Cancun. You might even hear them honking at you or flashing their lights in order to illicit a fare. Taxis are not metered in Cancun. Within the Hotel Zone, taxi fares will vary greatly. Some accounts range from $20USD for a couple of km, to $10 USD from mid-hotel zone to downtown. Discuss the price of your trip in total BEFORE you begin your ride. Paying in pesos will guarantee a cheaper rate. In downtown Cancun, all fares within the center of the city are $25 MXN. As with buses, it is important to carry smaller bills and coins. 

From the airport to anywhere: exclusive-taxis charge non-negotiable U.S. $40.00 or MX $400.00 (pay in any of the taxi stands inside the airport). From anywhere to airport: feel free to negotiate, but expect about MXP $200.00 pesos.

Taxis will not issue receipts, except if you buy within the airport taxi stand.

Rent-a-Cars:

It's better to rent a car only if you plan to move around a lot.  Remember you are in a foreign country, so be sure you insure your rental car appropriately. Parking is limited in the hotel zone.  Be careful of the Police, be familiar with ticket prices as they are looking for cash payouts when stopping tourist. A seat-belt ticket is $22 and speeding approximately. $100. Told $100 for seat belt  when stopped, confirmed by the station was $22. Be aware...