Gathering estimates on the number of gasoline powered vehicles within a specified region is difficult at best. There are very few public records available to see how many registered private and public automobiles there are within the U.S., not to mention aircraft and sea fairing operations. Certain numbers have the 2003 number for vehicles on American roads at 204,000,000, yet there are some that mark the statistic as high as 230,000,000. The last available numbers for global vehicle registration was in 1996 where there was about 485,954,000 cars, and 185,404,000 trucks and buses. The total was then clocked at 671,358,000. This is direct contrast to the 1900 assessment of only 4,192 transportation machines. (A Look at Statistics) It is much more difficult to get comparative statistics for airplanes and similar type vehicles, especially those used for large scale shipping and distribution.