If a choice between driving yourself or taking Thai public transportation such as a mini-bus, van or tourist bus, no question driving yourself is the safest method.
There are so many accidents in Thailand involving public transportation, that is almost hard to believe.
If you understand these companies hire non-professional drivers for less than 10,000 thb a month and drive them to the point of exhaustion/drug taking, it is easy to understand.
A person really has to understand how many of these accidents occur each year and ask themselves if it worth the risk?
Driving yourself presents some challenges as defensive driving and always be on the look-out is a must.