Advanced training in rational driving based on safety regulations
Domain 1 tests whether you can drive a heavy goods vehicle defensively, smoothly and with low fuel and wear costs. The exam looks for planned observation, correct speed choice, engine braking, progressive gear use and an understanding of how driver behaviour changes fuel consumption, emissions and risk. It is not a test of vehicle-handling tricks; it is a test of decisions made before and during a trip.
Plan before you move
Route choice, traffic information and delivery windows determine much of the day's fuel use. A route with fewer stops, fewer steep climbs and less congestion usually beats a shorter but stop-start route. Check tyre pressures when cold, remove unnecessary roof bars or loose covers, and know the vehicle's height, weight and turning circle before entering narrow streets.
Speed, gears and energy
Air resistance rises with the square of speed. At 80 km/h a lorry typically uses roughly 10–15% less fuel than at 90 km/h, and the time penalty on a 400 km trip is only about 33 minutes. Keep the engine in its efficient band, use block shifting, avoid labouring, and use cruise control only on dry, free-flowing roads. Engine braking and retarders save brake wear; on slippery surfaces use them gently and progressively. Idling for more than a short stop wastes fuel; switch off where the vehicle and auxiliaries allow.
Observation and space
Look 12–15 seconds ahead, use mirrors and blind-spot checks, and keep a space cushion. In Danish towns, expect cyclists and pedestrians at junctions; on motorways, watch for queues at exits and roadworks. Adjust speed so you can stop within the distance you can see to be clear.
Worked example
A 400 km motorway run at 90 km/h uses 32 l/100 km. Dropping to 80 km/h saves about 12%: 400 × 0.32 = 128 l; 128 × 0.12 = 15.4 l. At 12.50 DKK/l that is 192 DKK. Driving time rises from 4 h 27 min to 5 h, a 33-minute cost. If the schedule has 30 minutes of slack, the lower speed is rational; if it does not, the driver should challenge the plan rather than speed.
Traps
Treating the speed limit as a target; coasting in neutral; using cruise control in rain; overestimating time saved by speeding; ignoring tyre pressure; and braking late instead of planning ahead.