It’s not incredibly rude…and I don’t think it would sound so if you said it someone whom you’re pretty close to.
But I can also see how it sounds like an “order.” And it might make the one on the receiving end feel like they’re being bossed…hence perceived as rude.
^If that’s the case, then adding a couple of words might make it sound less “rude” to the person. Example: “Could you please try to pick me up at 4:45 because it takes 15 min to get to X.”
^You don’t know what state the other person (receiver) of the message might be in. Perhaps they were in a rush…or bogged down with something…or in a bad mood…when you sent the message.
Also depends on whom you’re saying it to. I’d more likely word it the way you did if I were talking to my sister…or a really close friend…someone whom I can be really frank with and don’t have to worry too much about formality with. But then again, I also know that if my sister, for example, was bogged down with something or stressed…she’d interpret my message as bossy and get annoyed.