More on Communting Costs

Thanks, everyone, for your feedback!

Just a little more information for y'all:

• There is no public transportation available.
• There are showers in my building, not 50 feet from my office. I could certainly use the showers after I got to work, if necessary.
• From what I understand, if it has working bicycle pedals and can't travel any faster than 20 mph under its own power, then it counts as a bicycle and no licensing is required.
• Supposedly, technology has gotten better and the electric motor is much quieter.
  
• I can't actually move much closer to work. It's five miles from the gate to my building, so that half of the distance can't be eliminated. The land surrounding the lab property either belongs to an industrial park, a neighboring lab, or it's contaminated, undeveloped land. The closest houses are probably seven miles from my building, which is still too far for me to walk, or bike without assistance.
• I could carpool; there is a woman down the street who works at the lab and she drove me to work during the weeks my arm was in a cast last summer. But I sometimes keep strange hours; if I'm on a roll on something I hate to quit just because it's 5:00. So I was hoping I could find an alternative method of transportation that would cut down on pollution but still make it possible for me to retain my working-hours autonomy.
  

It's unfortunate that there's no easy alternative mode of transportation. I'll have to decide if buying even a less expensive electric bike (like the ones Laura pointed out) would be worth doing. Would I actually use it or would it just be another thing collecting dust?