How do you do it. The reason why I play OTTD much more than this is because of the ability to realistically sepearate traffic, and the at the ease which it can be done. Sorry if this has been posted before, but I've searched everywhere, and cannot find solutions.
Timetabling requires Experimental.
Without experimental, this is done through having a station with multiple platforms (perhaps with chose signals) with some more separation at the end, where the vehicle can be set to wait for full load at various intervals (1/64, 1/32, etc), after which it will depart. This will provide spacing of vehicles along the line. This is more easier handled in Experimental, where departure frequency can be specifically defined.
As I thought, only experimental. Oh well.