"The typical 5-axle tractor-trailer combination" . . "truck traffic" . "articulated lorry" . "semi-trailer tractor" . "gladhands" . "side underrun protection system" . "Semi-trailer truck#Underride guard" . "big-rigs" . "transporter" . "tractor-trailer" . "heavy trucks" . "Semi-tractor" . "tractor trailers" . . "Tractor Trailer" . "semi-trailers" . . "underrode" . "Semi Truck" . "18-Wheeler" . "semi trucks" . "road-going trucks" . . "articulated lorries" . "truck trailers" . "semi-tractor" . "semi-trailer" . "18-wheeler tractor trailer" . "tractor trailer" . "rigs" . "semis" . "semi-trailer truck" . "tractor" . "Semi-Trucks" . . "commercial" . "tractor-trailer truck" . "long haul tractors" . "interstate trucking" . "18-wheel truck" . "road train" . "semi truck-trailer combinations" . . "prime mover" . "articulated trailer" . "transporters" . "Tractor-trailer trucks" . "Underride guard" . "truck driver" . "Semi-trailer truck" . "semi-trailer tractor units" . "18-wheeler trucks" . . "tractor-trailer combination" . . . "building truck" . "semi-trailer vehicles" . "big rig" . "Vehicle Dimensions and Mass 2016 rule" . "trucking industry" . "tractor-trailers" . "Semi tractor" . "articulated vehicle" . . "semi-truck" . . "Flatbed Trailer Truck" . "articulated truck" . "semi-tractors" . . "tractor truck" . . "18-wheeler truck" . . "semitrailer tractors" . "semi-tractor-trailer truck" . "heavy trailing" . "eighteen-wheeler" . "18-wheeler" . . . . "semi-trailer trucks" . "tractors" . "tractor-trailer trucks" . "Semitractor" . "truck designed to tow a semi-trailer" . . "18 wheel truck" . "Semi-trailer truck#Construction" . "Artic" . "Truck" . "tractor-trains" . "semi-trucks" . "highway trucks" . "trucks" . "tractor trailer trucks" . "articulated transport truck" . "semi-tractor trailers" . "underriding" . . "eighteen wheelers" . "Flatbed trailer truck" . "Semi-trailer truck" . "Articulated" . "18 wheelers" . "dry bulk trailer" . . "artic cab" . "Trucks" . "semi tractor" . "Trailers" . "truck and trailer" . "Semi-trailer truck marking lights" . . "18-wheelers" . "big rigs" . "semi" . "prime movers" . "18 wheeler" . "tractor-trailers (semi-trailer rigs)" . "Peterbilt 352H" . "Semi-trailer_truck#Trailers" . "weight cap" . "tractor / trailer" . . "underride guard" . . "articulated-lorry trailer" . "articulated" . "high productivity vehicles" . "semi truck" . "semi-trailer dump trucks" . . "vehicle trailers" . "eighteen-wheelers" . "truck" . "18-wheel tractor-trailer" . "transport vehicle" . "semi tractors" .