Answer:

semi

Answer	Crossword Clue
SEMI	Final preceder
SEMI	Highway hauler
SEMI	Interstate sight

SEMI	Rig
SEMI	Tractor-trailer
SEMI	18-wheeler
SEMI	Big rig
SEMI	Circular opening?
SEMI	Final intro?
SEMI	16-wheeler
SEMI	Automatic start

SEMI	Precedes precious and sweet
SEMI	Truck stop stopper
SEMI	Eighteen-wheeler, for short
SEMI	Interstate hauler
SEMI	Large Marge drives one in "Pee-wee's Big Adventure"
SEMI	CBer's truck
SEMI	Convoy component
SEMI	Type of truck

SEMI	Trucking rig
SEMI	Big truck
SEMI	Trailer
SEMI	Kind of final
SEMI	Highway behemoth
SEMI	Member of a convoy
SEMI	Highway giant
SEMI	Penultimate game

SEMI	Rig on the road
SEMI	Truck-stop sight
SEMI	Convoy member
SEMI	Pre-final match
SEMI	Half, to start with
SEMI	Second-to-last match
SEMI	Cab attachment
SEMI	Vehicle capable of jackknifing

SEMI	Highway heavyweight
SEMI	Long hauler
SEMI	Weigh-station stopper
SEMI	Half up front?
SEMI	Big roller