DOT pụtara Ngalaba Ụgbọ njem na United States, na ebumnuche nke ịhụ na America nwere usoro njem ụgbọ njem kachasị mma, nke kachasị arụ ọrụ na ọgbara ọhụrụ n'ụwa.

Ụdị ụgbọala na-adọkpụ nile, site n'ụgbọ mmiri na-adọkpụ, ndị na-ama ụlọikwuu na ụgbọala na-adọkpụ na-adọkpụ na-adọkpụ ruo 18-wheeler rigs, na ihe ọ bụla dị n'etiti, ga-enwerịrị ọkụ kwesịrị ekwesị tupu ha apụ n'okporo ụzọ. Dị ka United States Department of Transportation's National Highway Traffic Safety Administration nwere ihe siri ike chọrọ maka ọkụ ụgbọala na-adọkpụ, lelee usoro ọkụ nke ụgbọala na-adọkpụ iji hụ na ihe niile kwekọrọ n'iwu gọọmenti etiti tupu ị gawa n'okporo ụzọ mepere emepe nke pụtara.niileọkụ ụgbọala na-adọkpụmbupụ na North America ga-enwerịrị ya.

Anyị bụ otu n'ime ndị kasị ukwuuọkụ ụgbọala na-adọkpụụlọ ọrụ dị na China nke nwere ụlọ nyocha DOT na ọkụ ọ bụla ga-anwale ma kwado ya site na ọkọlọtọ DOT tupu ngwugwu na mbupu.

Nabata ịkpọtụrụ anyị na ọrụ, a ga-enye ihe nlele na ngụ n'efu.