Holbox is an island located 30 from Chiquila’s Harbor. Chiquila is around 2 hours drive from Cancun and Playa del Carmen. The highway is in very good condition. So don’t be worry to rent a car. It is an easy drive. You can also take some tips about renting a car here.
But if you are more in an adventurous or solo travelling experience, you can take a bus. It is cheaper and more comfortable. Because you have to pay $100 pesos every 24 hours of parking in Chiquila. Private transfers and even light aircraft shuttles are available.