This is a fork from the question What's the progressive form of 来る, 帰る and 行く.
So the question explained that when ている is conjugated with these movement verbs (or other verbs that are more or less instantaneous, causing state changes), it does not translate into the progressive form of the verb, rather than the subject now being in the state of the verb having happened. (Correct me if my understanding is incorrect)
So my question now is, how do I conjugate them if I really want to convey the progressive form? For this discussion, let's narrow it down to movement verbs like 来る, 帰る, and 行く. (Or does the same apply to other stative verbs as well?)
例えば、この会話を考えましょう。私は今電車に乗っていて、友達と電話していることを想像してください。
友人:「もうついた?」
私:「ううん、まだ。I am going there now.」
How should I translate the statement in English? Is there a way to translate the progressive tense of such movement verbs (In this case I think it should be 行く?) into the progressive sense literally as we have in English -ing, without changing it into other phrases with similar meaning (e.g. translating it to something like "I'm on my way there")?
EDIT: P.S. the sentence in the bracket is not the translation of the dialogue in Japanese, it is meant to be the second sentence after the first sentence, i.e. the sentence which I wanted to translate.
EDIT: Also related: When is Vている the continuation of action and when is it the continuation of state?