There are many names for the powerful trucks we call big rigs. Semi, tractor-trailer, and eighteen-wheeler are just a few of them. No matter what they're called, young truck lovers are always amazed at their immense size. In this motivating and accessible book, readers learn many fun facts about big rigs through the informative low-ATOS text and carefully selected photographs, which support the more challenging vocabulary terms. The bright and colorful design will attract truck enthusiasts of all reading levels.