Denmark Category TM Tractor Theory Test common mistakes
Denmark Category TM Tractor Theory Test · Understand the traps and how to avoid them.
Treating a tractor with a mounted implement as a car when judging right-of-way at an unsigned junction, and expecting the other driver to give way because the tractor is slow or large.
Candidates learn the car right-hand rule but do not transfer it to the tractor context, and they confuse 'the other driver will surely stop' with a legal obligation. The slow speed and size of the rig create a false sense of being seen and being entitled to proceed.
What to do instead
Drill the default rule until it is automatic: at an unsigned junction the vehicle coming from the right has right-of-way, regardless of vehicle type or size. Practise reading the junction type first (signs, lines, exit from field or private road) and only then deciding who yields. Remember that a vehicle emerging from a field, farm track, gravel road or private driveway must give way to all traffic on the public road.
Misreading the difference between a yield line and a stop line, and rolling through a junction where a solid stop line and STOP sign require a full stop.
On rural roads the markings are often worn, partly covered by gravel or mud, and viewed from a high tractor cab at an angle, so the candidate reads the situation as a normal give-way and never brings the rig to a complete halt.
What to do instead
Before the test, learn to identify the two markings by shape and context: a solid transverse line means a full stop with the front of the vehicle behind the line, a broken or triangular give-way marking means yield and proceed only when clear. In practice, approach every marked junction slowly enough that a full stop is still possible, and say out loud what marking you see. Check mirrors and the left side again after stopping, because a loaded trailer blocks much of the rear view.
Entering a roundabout without checking whether the tractor-trailer combination can complete the exit, then stopping inside the circulating carriageway or straddling lanes because the trailer cuts the corner.
Candidates plan the roundabout for the tractor alone and forget that the trailer tracks inside the tractor's path. They also underestimate how long the combination occupies the entry, so they commit when the gap is only big enough for a car.
What to do instead
Use the whole approach to judge the gap needed for the full combination, not just the tractor. Choose the lane that allows the trailer to sweep without mounting the apron or crossing into the inner lane, keep speed low and steady, and if the gap is doubtful, wait. On multi-lane roundabouts, hold your lane through the exit and check the trailer in the mirror before straightening out.
Following too closely at normal road speed because the candidate uses the car two-second gap and does not add distance for the trailer mass and the longer stopping distance.
The rule of thumb learned for cars is applied unchanged. A loaded trailer adds mass and, on many tractors, unbraked or lightly braked trailer weight, so the combination needs noticeably more road to stop. Candidates also keep the same gap when road surface is wet or gravel-covered.
What to do instead
Apply a larger gap for the combination and increase it further in rain, on gravel, or with a heavy or unbraked load. Practise judging the gap by counting seconds to a fixed roadside object and confirming you can stop within the visible clear road. Remember that the safe gap is set by the stopping distance of the whole combination, not by the tractor alone.
Coupling a trailer without confirming the mechanical lock has engaged and without a physical pull-test, then driving off with only the hydraulic or electric connection checked.
Candidates trust the sound of the coupling or the indicator on the hitch and skip the walk-around check. The pre-test nerves and time pressure push them to move off quickly after backing under the drawbar.
What to do instead
Follow a fixed coupling sequence every time: correct drawbar height, reverse slowly, listen and feel for the lock, then get out and visually confirm the locking pin or latch is fully home. Do a pull-test with the tractor against the trailer with the parking brake applied, connect the breakaway cable and the electrics, check lights and indicators with a helper or by reflection, and lower the support leg and raise the jockey wheel before moving.
Loading the trailer without checking the vertical load on the hitch and the axle loads, then discovering the combination is unstable or overloaded only when braking or on a slope.
Candidates focus on total weight and forget that the distribution of the load changes the load on the tractor's rear axle and the trailer's drawbar. A load placed too far back lightens the hitch and makes the trailer sway; too far forward overloads the tractor.
What to do instead
Learn the permitted total weight, axle loads and hitch vertical load for the tractor and trailer, and load so the weight sits slightly forward of the trailer axle within the hitch limit. Distribute heavy items low and centred, secure them against movement, and re-check the combination after the first few kilometres. If the trailer starts to sway, ease off the accelerator rather than braking hard.
Driving a tractor with an implement or trailer that is wider or longer than the permitted dimensions without the required marking, or with an insecure load protruding at the rear.
Candidates assume farm machinery is exempt from dimension and marking rules, or they simply do not know the thresholds at which lights, reflectors or warning markings become compulsory.
What to do instead
Learn the width, length and height limits that apply to the combination and the marking required when they are exceeded, including rear marking and lights for overhanging loads. Before every trip, walk around the rig and check that all lights, reflectors and warning panels are clean and working, that the load cannot shift, and that nothing protrudes unmarked. If in doubt about a dimension, measure rather than guess.
Judging an overtaking or turning manoeuvre only from the tractor's mirrors and forgetting the blind spot directly behind and beside the trailer, especially when turning right across a cycle path.
The tractor cab gives a good forward view but poor rearward view of the trailer's near side, and candidates rely on the mirror without a shoulder check. The high seating position hides cyclists and pedestrians close to the vehicle.
What to do instead
Before any turn, check mirrors, signal early, and use a direct look or mirror check for the near-side blind spot, slowing enough to let a cyclist or pedestrian clear. When turning right, keep the combination from swinging the trailer into the cycle lane, and give way to pedestrians and cyclists continuing straight. Treat every junction with a cycle path as a situation where someone may be alongside you unseen.
Underestimating the effect of alcohol, tiredness or medication on reaction time and deciding it is safe to drive a slow farm vehicle on a short trip.
Candidates think a short distance or a quiet rural road reduces the risk, and they do not connect fatigue after a long working day with the concentration needed for a heavy combination.
What to do instead
Treat the same limits and the same judgement as for any other vehicle: no driving above the legal alcohol limit and no driving when affected by drugs or medication that impairs you. Plan journeys so you are rested, take breaks, and stop driving if you feel drowsy. Know that a tractor on a public road is subject to the same traffic rules and the same consequences as a car.
Arriving at a collision involving the tractor and not securing the scene, not giving first aid within one's competence, and not calling the emergency services with the right information.
Candidates have read about first aid but have never rehearsed the sequence under stress, so they either freeze or move injured people who should not be moved.
What to do instead
Learn and rehearse the order: stop safely and switch on hazard lights, secure the scene with a warning triangle where safe, check for danger, call the emergency number and give location, number of casualties and hazards, then give first aid within your training, including stopping bleeding and keeping the injured person warm. Do not move an injured person unless there is immediate danger. Exchange details and report the incident as required.