Here are some useful links dealing with Highway travel:
General Highway
American Association of Motor Vehicle Administrators (AAMVA)
Commercial Vehicle Safety Alliance (CVSA)
Fraternal Order of Police (FOP)
Highway Watch (HWW)
International Association of Chiefs of Police (IACP)
National Sheriffs' Association (NSA)
National Safety Council (NSC)
National Defense Transportation Association (NDTA)
Society of Automotive Engineers (SAE)
Federal Highway
Customs and Border Protection (CBP)
Department of Defense (DOD)
Department of Energy (DOE)
Department of Homeland Security (DHS)
DHS – White House – State Departments of Homeland Security Offices
Federal Highway Administration (FHWA)
Federal Motor Carrier Safety Administration (FMCSA)
National Highway Traffic Safety Administration (NHTSA)
Nuclear Regulatory Commission (NRC)
Office for State and Local Government Coordination (OSLGC)
Passenger Highway
American Bus Association (ABA)
Bus Industry Safety Council (BISC)
International Motor Coach Group (IMG)
National Association for Pupil Transportation (NAPT)
National Association of State Directors of Pupil Transportation Services (NASDPTS)
National Motorcoach Network
National School Transportation Association (NSTA)
National Tour Association (NTA)
North American Bus Industries, Inc. (NABI)
Travel Industry Association (TIA)
United Motorcoach Association (UMA)
Infrastructure Highway
American Association of State Highway Transportation Officials (AASHTO)
American Underground Construction Association (AUA)
Intelligent Transportation Society of America (ITSA)
International Bridge, Tunnel, & Turnpike Association (IBTTA)
International Tunneling Association (ITA)
NACE International (formerly National Association of Corrosion Engineers) (NACE)
National Association of City Transportation Officials (NACTO)
National Governors Association (NGA)
Trucking Highway
American Trucking Associations (ATA)
Intermodal Association of North America (IANA)
Motor Freight Carriers Association (MFCA)
National Industrial Transportation League (NITL)
National Private Truck Council (NPTC)
National Tank Truck Carriers (NTTC)
Owner/Operator Independent Driver's Association (OOIDA)
Truck Manufacturers Association (TMA)
Truck Renting and Leasing Association (TRALA)