[TheMightyM]

There's a brief description of the Mayan Train project at Yucatan Expat Life. Some highlights:

The train is meant to get tourists off the beaten path, whisking them from bustling Cancun to less visited destinations, including Mérida, Izamal and Valladolid. It will reach as far as Palenque, in Chiapas, where archaeological ruins are the main attraction.

And:

The medium-speed train will connect 12 stations along more than 930 miles of track. The cost is likely to be between US$6 billion and US$8 billion, more than double previous estimates.