Indiana CDL General Knowledge common mistakes
Indiana CDL General Knowledge · Understand the traps and how to avoid them.
Reciting the pre-trip inspection items in the wrong order and skipping the in-cab check, brake test, and final walk-around, so the answer sequence omits steps the examiner expects.
Candidates memorize a loose list of parts (lights, tires, fluids) without anchoring it to the required sequence: approach and check condition, in-cab inspection, start and check gauges and warning lights, brake tests, then a final walk-around. The written exam tests the order and the purpose of each step, not just part names.
What to do instead
Build a fixed seven-step script (vehicle condition, in-cab, engine start and gauges, brake test, light check, final walk-around, documentation) and rehearse it aloud until the order is automatic. For each step, be able to state what you are checking for and what defect would put the vehicle out of service, because questions ask why a step exists, not only what it is.
Treating the air brake check as one item, so questions about static leak rate, applied leak rate, low-air warning, and spring brake pop-out get answered with the wrong test or the wrong sequence.
The four checks look similar and all involve holding the brake and watching the gauge. Candidates conflate them, or forget that the low-air warning and the spring brake emergency activation are separate checks performed at different pressure points.
What to do instead
Learn each check as its own card: what you do, what you watch, the pass criterion, and what failure means. Fix the order (static leak, applied leak, low-air warning, spring brake pop-out) and the pressure ranges in your memory. Practice explaining which check you would do first after a full build-up and why.
Answering stopping-distance and following-distance questions with gut feel, such as 'double the distance in rain', instead of applying the speed-based rule the exam expects.
Everyday driving habits feel correct, and candidates never convert speed into feet per second or match following distance to the vehicle type and conditions. The exam tests a specific rule for CMVs plus adjustments for speed, load, weather, and visibility.
What to do instead
Memorize the CMV following rule (one second per ten feet of vehicle length below 40 mph, adding a second above 40 mph) and the perception-reaction-plus-braking breakdown of total stopping distance. Work practice problems converting speed to feet per second so the arithmetic becomes routine, and note how weight, road surface, and grade change the result.
Mixing up which gear to use on a downgrade and when to downshift before a curve or hill, choosing to coast in neutral or shift mid-curve.
Candidates carry over manual-car habits (coast downhill, shift while turning) and do not connect gear selection to brake temperature and engine braking. The exam frames shifting as a control and safety decision, not a convenience.
What to do instead
Learn the rule that you select a gear before the downgrade that lets engine braking hold a safe speed without riding the brakes, and that you complete downshifts before entering a curve. Know why coasting in neutral is prohibited and why floating gears or skipping the clutch damages the transmission. Practice matching road speed to gear and RPM range for both upshifts and downshifts.
Describing a skid recovery as braking hard and steering away from the skid, or answering all skids the same way regardless of whether it is a drive-wheel, steer-wheel, or trailer skid.
Panic braking is the instinctive response, and candidates do not separate the causes: overbraking, oversteering, or acceleration. Each skid type has a different correction, and the exam tests the specific action and what to do first.
What to do instead
Memorize the correction per type: for a drive-wheel skid, stop accelerating or braking and steer in the direction you want to go; for a steer-wheel skid, release the brake to let the wheels roll and regain grip; for a trailer skid, stop braking or accelerating and steer to straighten. Know that the first move in any skid is to stop the action that caused it, and that locking wheels removes steering control.
Answering railroad crossing questions by describing a general 'stop, look, listen' without the CMV-specific requirements for vehicles that must always stop, the gear selected before crossing, and what to do if the vehicle stalls on the tracks.
Candidates assume the crossing rules they learned for cars apply. The exam tests which CMVs must stop at every crossing, why you never change gears while crossing, and the evacuation procedure if you stall.
What to do instead
Learn which vehicles must stop at all crossings (for example those carrying passengers or hazardous materials, and school buses) and the rule to select a gear before the tracks and not shift while crossing. Memorize the stall procedure: get everyone out and away, then call the railroad or emergency number posted at the crossing. Practice identifying the crossing signals and gate behavior.
Treating hours-of-service as a single driving limit, so questions about the on-duty window, required breaks, reset, and the difference between on-duty not driving and driving get answered with the wrong clock.
The rules stack several limits that run on different clocks (driving limit, on-duty window, break requirement, cycle limit, reset). Candidates remember one number and apply it to every question, and they misclassify activities such as loading or waiting time.
What to do instead
Draw the clocks side by side and label each: driving limit, on-duty window, the break requirement, the cycle limit, and the reset. For each activity (driving, on-duty not driving, off duty, sleeper berth), decide which clocks it counts against. Then work scenario questions where one clock expires before another and identify which limit binds first.
Answering cargo questions by naming tie-down types without tying the number of securements, working load limit, and aggregate limit to the load's weight and length.
Candidates memorize hardware names but not the arithmetic that determines how many securements are needed, and they confuse the rating of a tie-down with the strength of the anchor point. The exam tests the rule, not the vocabulary.
What to do instead
Learn the requirement that the combined working load limit of the securements must be at least half the cargo weight, plus the minimum number of tie-downs based on cargo length. Practice problems computing needed securements from weight and WLL, and know that each anchor point's rating caps what a tie-down can contribute. Also review load limits and axle weight distribution.
Mishandling hazardous materials awareness questions by guessing placard thresholds and forgetting that the driver must know the shipping paper location, emergency response information, and when to refuse or segregate a load.
Hazmat rules are numerous and candidates skim them, assuming the general knowledge exam will not probe specifics. They confuse placard requirements with package marking and forget the driver's document and emergency-response responsibilities.
What to do instead
Build a short reference for what the driver must carry and know: shipping paper accessibility, emergency response information, placard placement and when placards are required, and loading rules such as keeping incompatible materials apart. Focus on the driver's awareness duties rather than chemical detail, and practice questions about a shipment that is mislabeled or leaking.
Describing post-accident actions out of order, such as moving the vehicle before protecting the scene, or omitting notification, injury care, and the requirement to stop and exchange information.
Candidates list actions as a set rather than a sequence and skip steps under pressure. The exam tests priority: protect the scene, then care for the injured, then notify, then document.
What to do instead
Memorize a fixed sequence: stop and secure the scene (warning devices, hazards), check for injuries and call for help, notify authorities, exchange required information, then document and report to the carrier. Know when moving the vehicle is permitted and where warning devices go at different speeds. Rehearse the sequence as a numbered list so priority questions resolve quickly.