We are thinking of checking out Coba this year for a day trip. Any advice? What is best way to get there, besides renting a car (which we prefer not to do)?
Aside from renting a car the only halfway convenient way to get there is on a tour bus. I do not believe that buses go out that road towards Coba. At least all the people on the riviera maya board have not heard of one. You could take the bus to Tulum and then a taxi over to the ruins, but that would probably be very costly. I will let you know if I think of anything else.
This tour is supposed to be great: http://www.alltournative.com/tours-products/maya-encounter We've always just driven to Coba. Be sure to rent bikes while you are there, it's the best way to see the ruins.
Actually Val, I was looking into buses from Valladolid to Tulum for a friend and it seems that they do go through the Coba area as well. It would still make for a long day busing it from Cancun to Tulum or Playa then over there, and all the way back at the end of the day. In general I hate group tours, but if I was not driving there, I would probably opt for a tour to make life easier.