(4)The publication of a time table under which, or the giving of any direction that any journey or part of a journey is to be completed within a specified time shall, if in the opinion of the Court it is not practicable in the circumstances of the case for that journey or part of a journey to be completed in the specified time without contravening the speed limits referred to in section 112 be prima facie evidence that the person who published the time table or gave the direction has committed an offence punishable under [sub-section (1)].