I've got a 30-mile commute. Work dress is casual, so no problems for me wearing something under my gear, but sometimes when it's hot I just wear MX-style knee/shin guards under my firehose jeans. One trick for me is to keep a spare pair of pants, a belt, and a comfy pair of shoes at work. That saves me forgetting to bring pants if I'm wearing mesh pants in the summer, or forgetting shoes. Also, the pants come in handy if I get soaked for some reason on my ride (sudden thunderstorm).
For my part, I travel not to go anywhere, but to go. I travel for travel's sake. The great affair is to move. Robert Louis Stevenson