Why?
Probably, as you mentioned, so he could stop and take pictures. Although assuming you don't need a car there at all (which I can't assume), I imagine a taxi wouldn't mind stopping along the way for a few minutes so you can take pictures. It'd be a lot harder if you were a professional photographer, taking 10+ minutes to compose shots and change lenses, etc, but I don't think it'd add too much to the cost of the fare.