Green hybrid has a fairly huge mileage database.
Civic Hybrid I auto(cvt) average- 46
Civic Hybrid I manual average- 48
Insight auto(cvt) average- 55
Insight manual average- 65
http://www.greenhybrid.com/compare/mileage/
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2008 EPA adjusted:

Distance traveled by bicycle in 2007= 1,830ish miles
Average commute speed=25mph (yes, that's in a car)