Before I start this thread with a nice meaty OP to set the ball rolling, can I just get one little question out the way?

My train to Nonkhai arrives at 0930, and of course it may well be late.

I am concerned that I may not have enough time to get to the checkpoint to leave Thailand before it closes and I have just been back to my travel agent to change it to the earlier train but I can't - not unless I wants to stand up all the way from Don Muang, screw that - I'd rather pay the 500 overstay.

So how much time do I have to get there before closing?