CDL Combination Vehicles Practice Test Results

Question 1
89% answer correctly
When is the proper time to use the trailer handbrake to straighten out a trailer that`s jackknifing?
In the middle of the jackknife
When you start to recover from the jackknife
Never
As soon as you start to jackknife
Question 2
90% answer correctly
Which of the following statements about combination vehicles is true?
Driving combination vehicles is no different than driving single commercial vehicles
All of these are true
They`re heavier, longer and require more driving skill than single commercial vehicles
Single commercial vehicles are heavier, longer and require more driving skill than combination vehicles
Question 3
60% answer correctly
After pushing in the trailer supply valve you should not move the tractor until:
The entire air system is above 120 psi and the warning buzzer has stopped
The entire air system is above 60 psi and the warning buzzer has stopped
The warning buzzer has stopped
The entire air system is above 120 psi