My daughter and I commute to her school an a K2 mtn bike and a "Trail-a-bike" third wheel. Our route is pretty much a straight shot on a major road. Lots of traffic! Oh, well.
I'm sort of a fitness nut, or as my daughter and wife have labeled me, "Crazy Running Man Fool."(Not quite sure of the meaning but it was created with the best of intentions!) I'm also very concerned with how I affect the environment around me. I strive to create a negative footprint on the earth.
Even if your intentions are only to save money on vehicles, I still applaud you for making an earth healthy decision to ride your bike!