USDOT Resource Links
http://www.fhwa.dot.gov/webstate.htm   State Transportation Web Sites
http://www.dot.gov/   US Department of Transportation
http://www.fmcsa.dot.gov/  Federal Motor Carrier Safety Administration
What is a USDOT Number? Companies that operate commercial vehicles transporting passengers or hauling cargo in interstate commerce must
be registered with the FMCSA and must have a USDOT Number. Also, commercial intrastate hazardous materials carriers who haul quantities
requiring a safety permit must register for a USDOT Number. The USDOT Number serves as a unique identifier when collecting and monitoring a
company’s safety information acquired during audits, compliance reviews, crash investigations, and inspections.
More...
http://www.fhwa.dot.gov/  Federal Highway Administration
http://www.dotauthority.com/ DOT Authority.com
Some States Require USDOT Numbers
In select states (see green highlighted states or list below), all registrants
of commercial motor vehicles, even intrastate and non-Motor Carrier
registrants, are required to obtain a USDOT Number as a necessary
condition for commercial vehicle registration.
* Information provided on this page is intended direct individuals to the
authority's that can answer all of your questions. Please research thoroughly.