IN CDL Combination case studies
IN CDL Combination · Put your knowledge to work in context.
The Indiana CDL Combination Vehicles knowledge test is the written endorsement exam a commercial driver takes to be cleared for tractor-trailer and other multi-unit rigs. It is aimed at drivers who already hold or are working toward an Indiana commercial driver's license and who need the combination vehicles classification on their record before they can legally operate a tractor-trailer, doubles, or a truck towing a heavy trailer. The IN CDL Combination case studies are 5 cases and about 3,264 words.
1Loaded Van, Stuck Fifth Wheel, and a Dispatcher in a Hurry
For the past three weeks you have pulled the same 2019 tractor with a 53-foot air-ride van, and every morning the fifth wheel release handle has gotten harder to pull. This morning the trailer is loaded to 44,000 pounds, the yard is packed gravel with a slight crown, and the handle will not move at all.
688 words, about 3 min2Right Turn, Slid-Back Trailer Axles, and a Cyclist
You are driving a 3-axle tractor with tandem drive axles pulling a 53-foot trailer whose axles are slid all the way back, giving a 51-foot distance from the kingpin to the trailer's rear axle. You are turning right from a four-lane arterial onto a two-lane street in a downtown grid.
686 words, about 3 min3Cold-Morning Leak-Down on a Combination
At 0600 in 20°F weather you do your pre-trip on a tractor-trailer combination that sat overnight. You build air to governor cutout at 128 psi and shut the engine off.
649 words, about 3 min4Wet 6 Percent Grade, Trailer Hand Valve, and a Jackknife
You are descending a 6 percent grade on a two-lane mountain highway in a 5-axle combination, grossing 78,000 pounds, with the trailer loaded with gravel. The road is wet from a morning rain and the temperature is 34°F.
643 words, about 3 min5Rapid Air Loss at Highway Speed
At 55 mph in the center lane of a four-lane divided highway you hear the low-air warning and see the primary gauge falling from 95 psi to 62 psi in about four seconds. You are pulling an empty 53-foot van at 34,000 pounds gross.
598 words, about 3 min