So, the question is, in Russian, does следовать correspond mostly to meaning 1. or 2.?
It corresponds to meaning 1: opinion, instruction or advice. Although a shade of implicit meaning of expectation is always there, as long as expressing advice implies the expectation that this advice will be taken, it can't be used to express an explicit expectation, like in "The train should (is expected to) arrive soon". Well, at least I can't think of an example where "следует" would explicitly mean "is expected".
- "Сделать работу как следует" = "To do the job properly", literally "To do a job as it should be done". Although this one is idiomatic, it can be taken quite literally.
- Context: someone is reflecting on the surprising outcome of an experiment, and finally realizing that such outcome makes perfect sense
"Этого результата следовало ожидать" = "That outcome should have been anticipated".
- "Следует заключить, что ..." = "One must conclude that ..."
- "Для нахождения площади круга следует радиус возвести ..." = "To find the area of a circle, one should take the radius to the power ...".
- Supreme Court rulings, explaining to the courts of first instance how certain laws should be applied, often use wording "... следует руководствоваться нормами ..." = "... must be guided by the rules of ... [article NNN]".
Note that this meaning is possible only if there's no subject to this verb. "Я следую" always means "I follow" or some other motion-like meaning. To get the "ought to" meaning you must use some impersonal form:
- If there's no definite subject in the English sentence, then there should be no subject in Russian either: "It should be noted that ..." = "One should note that ..." = "Следует отметить, что ...".
- If there's a definite subject in English, it should be put in the dative case (which means it's not a subject any more): "I should ..." = "Мне следует ..."
That's a strange translation, in English. Not sure what it means because we wouldn't say the sentence "he should urgently arrive at the station."
What would you say if, for example, some emergency just came up at the station, and the officer on duty was calling for a medic (or a firefighter, or just general reinforcement) and said that they should come as soon as possible?