I found this interesting citation in "The Art of Natural Building" book online at this address:
http://books.google.com/books?id=054_i8KdcCAC&pg=PA118&lpg=PA118&dq=a+tamped+road+based+floor&source=web&ots=4UAQWsps_K&sig=ypUaQec_WMC7DEUPSfDs2iCd9tc&hl=en&sa=X&oi=book_result&resnum=1&ct=result#PPA118,M1
Interesting and nearly the same as we did on our front porch except we used cob so it was wetter and had straw in it.