Some symbols in Highway Kings offer bonuses for combinations of three or more, but the higher-income icons are only two matching rewards. The most generous sign on the board - the red truck - even pays two points for a single symbol on the reel.
Red trucks are wild and can replace all symbols to help you win prizes. In addition, wild doubles any victory, it helps to form, but not cumulative. In other words, the two wild symbols still multiply the victory by 2 instead of 4. The red truck symbol appears only on the center three reels.