GasBuddy http://www.gasbuddy.com/Gas_Prices/ The EIA and GasBuddy databases provided average gas price data at state and county levels. These statistics, combined with per capita income, yielded gasoline expenditure.
State Departments of Transportation
Vehicle Miles Travelled per County were provided by each of the state DOTs. Combined with the national average mileage/gallon of the current on-road vehicle fleet, these statistics yielded annual state-level and county-level gasoline consumption