Honeydutch, first off ... not wanting to insult you or anything ... but I find it strange that a 20 year old calls 16 miles a "long ride".
16 miles may seem like a lot for a commuter, but for a cyclist this is peanuts.
Things like 100 miles are considered pretty short stages in cycling.

This is all a very personal thing, so if 16 miles is a lot for you then I congratulate you and wish you courage and fun in your future cycling.
If you start doing this on a regular basis you'll notice that after a while your speed will be greater and you will start doing longer distances.

To give you an idea of how fast people ride ... in 1 hour:

-slow riders go about 10 miles
-normal riders go about 14 miles
-good riders go about 17 miles
-fast riders go about 21 miles
-cancellara goes more than 30 miles

I'm at about 22 now ... and training for more.