I planned to save a few dollars, reduce green house emissions, and better my health. I bought a $500 used road bike, and planned to commute to work a lot.
Immediately I realized that the roads are taken care of like crap. On one steep hill I have to take a lane to avoid potholes. I was going 20+ mph in the lane, and a car tried passing me driving over the solid-double-yellow lines. Then oncoming traffic made the car push me over. Going 20+ over bad potholes...got a flat rear tire.
Then traveling down a steep hill, only doing about 15mph (got the brakes on a bit, kinda scared of the last time...) and someone flies past me in a pick-up, hits the breaks hard, and takes a right-hand-turn, right in front of me. The car behind him locks up not to rear end him. I slow down as quickly as I can, stopping 2 feet from his truck. He stops completely, parked, for a few seconds, staring at the car that almost hit him. I wait a second, expecting him to give a I'm-sorry-wave to me, or something. But he then gets on the gas and continues, never even realizing I existed.
I've put less than 70 miles on my bike.
Money savings: I spent more on gas because of the broken bike than I saved riding it.
Environment: See above.
Health: I have slightly reduced my chance of heart attack, but greatly increased my chance of death-by-auto (not to mention the stress).