Some countries count only selected populations of trucks, and possibly use varying methods for counting other vehicle types as well. Although all known variations between data are noted in footnotes, it is possible that some were not apparent from the original data sources and so are not noted. The data on automobiles per population unit clearly show the disparity between Mexico and Chile and the more developed countries. While the U.S., as a large populous country, is far ahead in total kilometers, the differences in kilometers per vehicle and kilometers per person are much less. The data on average amounts of travel by the various vehicle types most likely reflects the types of uses of these vehicles as well as the geography and preferences of the country.
Fuel prices vary widely between countries and reflect full costs including applicable taxes.
More than 50 percent of gasoline prices in the European countries can be attributed to taxes. While diesel fuel taxes are less than those on gasoline they are substantial by comparison with those imposed in the United States. The data in this section came from reliable published sources which are noted with the individual tables. Ultimately, all Data came from the source countries. Data collection methods, definitions of terms, and basically political and economic infrastructures vary from country to country.