2026 Washington Combination CDL Practice Test 3

You are coupling a tractor to a semi-trailer and have backed up but are not under it. What should you hook up before backing under?

The electrical service cable The emergency and service air lines Nothing; back up and lock the fifth wheel

The emergency and service air lines

Access more questions from this quiz

Continue to 2026 Washington Combination CDL Practice Test 3 for more practice questions and the full quiz experience.