In all my years in Bangkok I learned not to bother with parked taxis always flag down a moving one.
Exception maybe busy taxi "ranks" where the taxis are taken so quickly that they are basically in a moving line. Chatuchuck/Mo Chit BTS going north in rush hour is an example of this.
From my experience the "Songthaews" in CM are not as good as the ones in Bangkok or Pattaya.
The roof of the trucks in CM is too low and passengers cannot see out so do not know where they are or where the have been. Not much use for tourists.
OK that's your advice but "the law says"? Maybe you were in the pub.
Maybe i'll give up helping people when they ask questions and join the masses with opinions.
If it is a worn out thread subject then someone knows the actual answer?
Is it mandatory to carry passport at all times or do we get 24hrs to produce passport or maybe a 2000 baht fine.
Not my discussion. Asking for a friend!
We should not discourage the Op from doing what he wants to do.
Not all roads are bad. I agree some smaller roads are atrocious especially concrete ones but most major roads are OK. At least where I live.
If it is a nice sunny day I cannot see any real reason not to ride from Pattaya to Koh Chang. I am not sure I would ride back the same day. I would probably stay overnight. If the OP wants or needs he can split the journey into 30minute stints.
One ride I considered was 380 kms and I would have split that in two as the last half is serpentine and could be tiring. Then again when younger I have dome Udon Thani to Bangkok (550kms +) in one day. But that is just me.
One is either a motorcyclist or or one is not. A motorcyclist would not even ask.
I have mates who want to stop at every Amazon for a coffee. Me? I fill the gas tank and ride until it is empty.
The OP will not know until he has tried. A PCX will cruise at 80kph+ all day even my Zoomer will do that.