Thanks to Alekso Minotaur, you can take a ride through the Transtiberim sim on a comfortable Saturnalia Sleigh. You can even invite some friends to ride along. Just be careful of the icy roads! If you hit too many rough spots, the structural integrity of the sleigh just may not hold!
You can find the Saturnalia Sleigh stall just outside Ostia in the ROMA Transtiberim sim.