I'd say here it's probably a 50/50 mix of commuters who wear lycra and those who wear more casual clothes. I don't see to, to many people who commute in their actual office duds, just because it's hilly and you do sweat and our weather can be a bit unpredictable... I do see a few especially if the weather is nice. If they are young twenty somethings with white shirts and ties on, I usually think they are Mormon missionaries before I think officer worker though...

We also have a large number of racing teams and a lot of us also commute. I commute in my race kit. I'd have to be too restrained to not get to work sweaty and dirty... I do have a locker room, towels and showers available to me at work, so I don't have to worry about anything. If I'm doing really short errand running or towing my trailer I'll usually dress casual.