Dear Arnt, The cost of maintaining and building roads is supposed to be paid for by vehicle use taxes whether through vehicle licensing or fuel taxes. I have a mining operation which uses diesel fuel and we do not pay road use taxes on this diesel fuel as it is all off road use, however, there is still poliution from the equipment. If you will notice on the back of some US semi's, the sign "this truck pays $0000's of dollars in road use taxes", the vehicle reports the milage in each state and pays a fee which is disbursed to each state. There would be a way the government would still assess the taxes regardless of the source of fuel. Tom Taylor The Gasification List is sponsored by USDOE BioPower Program http://www.eren.doe.gov/biopower/ and PRM Energy Systems http://www.prmenergy.com Other Sponsors, Archives and Information http://www.crest.org/renewables/gasification-list-archive http://solstice.crest.org/renewables/biomass-info/gasref.shtml http://www.crest.org/renewables/biomass-info/ http://www.crest.org/renewables/biomass-info/carbon.shtml