Gave it a shot myself, and honestly the wait time is a bit long especially when travelling alone. I found myself rather than roleplaying by myself, or staring at the inside of the carriage, windowing out because it was less than enjoyable for me.
I mean, we're talking 3 minutes just for the caravan to leave and then 12 minutes travel time? That's 30 minutes round trip and like Aahz said not everyone has the entire day to play so that 30 minutes really cuts into being able to arrive at the destination and enjoy the roleplay there.
Just my thoughts... cut down the time to 5 minutes total once the trip is paid for. That allows for some decent roleplay while players wait for the departure, but not too much time between point A to point B.