Translation:It only takes an hour and a half to drive there.
Yeah. It's still a measure word here. It definitely doesn't map to "and". What it's teaching us here is that in Chinese, a measure word indicates one WHOLE unit of a thing, so seeing it along with "半" means both a half and one or more whole units.
But I translated it as "half an hour" too. You live, you learn. We'll get it right next time.
You can say " a half hour" or "half an hour", but not "an half..." http://editingandwritingservices.com/a-or-an-before-words-beginning-with-h/ has some good tips for this.