AF Commercial Driving Theory common mistakes
AF Commercial Driving Theory · Understand the traps and how to avoid them.
Answering driver-hours questions from memory of what 'feels' like a full rest period rather than counting the actual daily and weekly rest minimums against the stated times.
Daily rest (11 hours reducible to 9, three times between weekly rests), weekly rest (45 hours reducible to 24) and compensatory rest are easy to conflate, and candidates often recall the reduced figures as the default.
What to do instead
Before answering, write the stated rest/ duty times on scratch paper and check each against the standard minimum first, then the permitted reductions and how many times they may be used.
Treating a 'no entry' or 'no vehicles' sign as applying only to the vehicle category shown in the question rather than to all motor vehicles.
Candidates pattern-match the sign image to the vehicle they drive instead of reading the sign's legal meaning, and confuse it with width/weight restriction plates.
What to do instead
Learn the sign by its legal category (prohibited to all vehicles vs. prohibitions qualified by a plate). For each sign, state aloud what class of traffic it prohibits before choosing an answer.
Selecting an action for a hazard (e.g. a cyclist ahead, a junction) that assumes other road users will behave correctly.
Candidates answer what they would like to happen rather than the defensive option; the 'correct' answer is usually the one that gives margin for others' errors.
What to do instead
For every hazard question, eliminate any option that relies on another road user yielding, signalling correctly, or seeing you, then choose from what remains.
Mixing up gross vehicle weight, gross train weight and axle weights when answering load/weight questions.
The terms sound similar and candidates apply the plated gross train weight to a solo vehicle or ignore the per-axle limit.
What to do instead
Memorise the plated definitions: GVW = vehicle plus load; GTW = vehicle plus trailer plus loads; axle limits apply individually. Re-read the question to see which figure is being asked about.
Describing load securing in general terms ('strap it down well') instead of naming the principle being tested.
Candidates know the practical habit but not the underlying requirement, so they miss options about restraint against forward, rearward and lateral forces.
What to do instead
Learn that loads must be restrained against forces in all directions, including emergency braking and cornering, and that the restraint system must be rated for the load. Match options to that principle.
Answering first-aid and incident questions with actions in the wrong order (e.g. moving a casualty before making the scene safe, or removing a helmet).
Candidates focus on the injury rather than the sequence: scene safety, then emergency services, then care within one's competence.
What to do instead
Apply a fixed order to every incident question: protect the scene, alert emergency services with location and details, then give care you are trained for. Reject any option that moves a casualty or removes a helmet unless there is immediate danger.
Confusing the daily walk-round check with the periodic (e.g. six-weekly) inspection and answering maintenance questions with the wrong interval or the wrong person responsible.
The two regimes overlap in candidates' minds and the responsible person for each is different.
What to do instead
Separate them explicitly: the driver's daily check covers tyres, lights, brakes feel, fluids and load security before moving; scheduled inspections are the operator's responsibility at set intervals. Answer according to which one the question describes.
Ignoring the effect of vehicle size and weight on stopping distance and safe following gaps, and answering with car-based figures.
Candidates learn to drive in cars and carry over the two-second rule and car braking distances without adjusting for laden weight and air brakes.
What to do instead
Use the larger gap appropriate to a heavy vehicle (at least four seconds in good conditions, more when laden or wet) and remember that air-brake lag adds to reaction and build-up time.
Treating documentation questions (licence categories, CPC, operator licence, tachograph records) as general knowledge and guessing which document proves what.
Candidates know the documents exist but not which one must be carried, produced, or kept for how long.
What to do instead
Build a short table: document, who holds it, whether it must be carried in the vehicle, and the retention or production period. Revise from that table rather than from prose.
Missing the qualifier in road-traffic-rule questions (e.g. 'unless', 'except', 'when signalled') and choosing the general rule.
Under time pressure candidates read the stem once and answer the familiar rule, ignoring a condition that reverses the correct answer.
What to do instead
Underline or note every qualifier and negative in the question before looking at the options, then check the chosen option against each qualifier.