Iowa CDL Combination Vehicles Test case studies
Iowa CDL Combination Vehicles Test · Put your knowledge to work in context.
Iowa issues Commercial Driver's Licenses through the Iowa DOT, and a driver who operates - or plans to operate - a tractor-trailer, a truck towing a heavy trailer, or another articulated unit must pass a combination vehicles knowledge test as part of the Class A process. This page targets that specific written test rather than the entire CDL battery. The Iowa CDL Combination Vehicles Test case studies are 5 cases and about 2,349 words.
1Pre-Trip Air Leak After a Trailer Brake Chamber Replacement
At 06:10 on a 38°F morning, you are doing a pre-trip on a 2021 tractor with a 53-foot dry van. The shop replaced the right-rear trailer brake chamber yesterday and manually adjusted that wheel’s automatic slack adjuster.
511 words, about 3 min2Coupling to a Trailer That Is Too High and Off Line
You are picking up a loaded 53-foot van at a shipper’s dock. The trailer kingpin is 49 inches above the ground; your fifth-wheel plate is 47 inches.
472 words, about 2 min3Trailer Brakes Fade on a 7% Downgrade
You are driving an 80,000-pound tractor-trailer down a 7% mountain grade that runs for 4 miles. The speed limit for trucks is 45 mph, and you are in 8th gear at 50 mph.
479 words, about 2 min4Right Turn With Severe Off-Tracking, Then a Raised Railroad Crossing
You are driving a 75-foot tractor-trailer (tractor plus 53-foot trailer) on a four-lane road and want to turn right onto a two-lane road. The right-turn lane is 12 feet wide; the curb radius is tight, and a utility pole sits 18 feet from the curb at the corner.
468 words, about 2 min5Rear Trailer Swing and Jackknife in a Curve
You are pulling two 28-foot pup trailers with a 77,000-pound gross weight on a two-lane highway. The rear pup is lightly loaded at 5,000 pounds; the lead pup is near 20,000 pounds.
419 words, about 2 min