click here for disclaimer document starts on next page techniques estimating mobile2 variables final report prepared test and evaluation branch emission control technology division office of mobile source air pollution noise radiation us environmental protection agency ann arbor michigan by energy analysis inc 1111 n 19th street arlington virginia 22209 july 1980 table contents 1 introduction organization 2 data sources general 3 state local 10 mileage accumulation age light duty vehicles heavy trucks 4 motorcycles 12 vehicle registrations method 6 14 24 5 26 humidity methodology potential uncertainties temperature vehiclemiles traveled