I'm travelling from Mukdahan to Ubon in a few days. I will (I guess) be able to leave Mukdahan at 3 PM after returning from Savannakhet. Any suggestions on mode of transport (not taxi)?

Plenty of buses leaving although not heaps that late in the afternoon. Another option is one of the bigger hotel mini vans who link up with Bangkok flights to Ubon.

White vans with green and yellow stripes. I have no idea of the schedule, my guess would be no more than a 30 min. wait at that time of day.

White vans with green and yellow stripes. I have no idea of the schedule, my guess would be no more than a 30 min. wait at that time of day.

Yep, can confirm that. Vans with aircon and not too many seats leave every 30 minutes to Ubon bus terminal.

Around 2 hours and 40 minutes. It's as fast as driving your own car.

P.S. Not all vans have green and yellow stripes.

https://www.google.co.th/?gws_rd=cr,ssl&ei=LmC8VMPLI9fj8AX6koLICw#q=From+Mukdahahn+to+Ubon+Ratchathani+distance

White vans with green and yellow stripes. I have no idea of the schedule, my guess would be no more than a 30 min. wait at that time of day.

Yep, can confirm that. Vans with aircon and not too many seats leave every 30 minutes to Ubon bus terminal.

Around 2 hours and 40 minutes. It's as fast as driving your own car.

P.S. Not all vans have green and yellow stripes.

https://www.google.co.th/?gws_rd=cr,ssl&ei=LmC8VMPLI9fj8AX6koLICw#q=From+Mukdahahn+to+Ubon+Ratchathani+distance

Thanks. If I took a regular bus what would be the time it takes to travel to Ubon? I am not a big fan of vans due to the way they drive in Thailand so would prefer a regular bus.