Just another student too, but I think "yuē yīgè xiǎoshí" must be functioning as a sort of adjective modifying the "drive time to the beach" part of the sentence, so there's no in front (eg, Wǒ hěn gāoxìng. No between the subject and adjective).. I'd like to know the real answer too but that's all I could come up with after searching online for a while. It's an interesting question.

Hi, although I'm HSK1 - HSK2 level I will try to answer your question. Please don't rely on my answer as being correct, just think of it as an opinion of a fellow student.

Definitions: chē chéng travel time; expected time for a car journey), (约 yuē approximately).

Phrase 车程约 chē chéng yuē - ride takes about; journey takes approximately.

I hope this was helpful.