The only thing I can see changing 'normal' peoples' attitudes about cycling would be a huge spike in gas prices. If gas went over $10 a gallon, commuting might start to become a serious option for them.
Right now, I can save $4 or so in gas with a 30 mile r/t commute every day (of course I'm not out there for the $4 payback on a couple hours of riding...). But, if it came out to more like $20 a day or more, I might start seeing some other people out there at 5 a.m.
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Campione Del Mondo Immaginario