I can't really do much as far as making it longer... or shorter

the road that I drive on is very narrow and twisty/hilly with a 55mph speed limit. Definately not a bike friendly route. So I end up riding my bike into one city, then taking a highway with a wide shoulder to the city where I work. I could lengthen the ride I suppose but then I'd end up having to double back to get on route. I think 50 miles round trip is plenty long enough though It was dark when I left in the morning and the sun was close to setting when I got home.