LK DMT Heavy Vehicle Written study guide
LK DMT Heavy Vehicle Written · Work through your exam, one topic at a time.
The heavy vehicle written examination administered through Sri Lanka's Department of Motor Traffic (DMT) is the knowledge-testing stage for drivers seeking to upgrade an existing licence to a heavy vehicle class, typically for lorries, buses and similar large vehicles. It is aimed at drivers who already hold a lighter vehicle licence and now need to demonstrate that they understand the rules, responsibilities and risks that change when the vehicle gets bigger and heavier. The LK DMT Heavy Vehicle Written study guide has 6 sections and about 1,741 words.
01Road Rules for Heavy Vehicles
Road rules for heavy vehicles combine the general rules every driver obeys with extra obligations that arise from size, weight and stopping distance. You must understand priority rules at junctions and roundabouts, overtaking restrictions, speed limits (including lower limits for lorries and buses where posted), safe following distance, parking and stopping prohibitions, and rules for pedestrians and cyclists.
280 words, about 1 min02Traffic Signs, Signals and Road Markings
You must be able to read three families of information: signs (regulatory, warning, information), signals (police, traffic lights, hand signals) and road markings (lines, arrows, box junctions, hatched areas). Regulatory signs such as stop, give way, no entry and speed limits are mandatory; warning signs are usually triangular with a red border; information signs are rectangular.
271 words, about 1 min03Heavy Vehicle Driving Technique, Handling and Load Security
Heavy vehicles behave differently from cars because of mass, height and length. You must understand: longer braking distances and brake fade on long descents (use a lower gear and engine braking, not continuous service braking); reduced acceleration when loaded; wider turning circles and off-tracking (the rear wheels cut inside the front wheels); and the effect of a high centre of gravity, which increases rollover risk in fast cornering.
245 words, about 1 min04Vehicle Inspection, Maintenance and Defect Awareness
A professional driver inspects the vehicle before each journey and reports defects. Know the daily walk-around checks: tyres (tread depth, pressure, cuts, bulges, correct matching on an axle), wheels and nuts, brakes (including air pressure build-up and low-pressure warning), lights and reflectors, mirrors, wipers, horn, steering play, suspension, fluid levels, and load restraints.
240 words, about 1 min05Road Safety, Hazard Perception and Accident Prevention
Hazard perception is the skill of seeing risk early and planning a response. You must scan far ahead, use mirrors frequently, and maintain a space cushion around the vehicle.
255 words, about 1 min06Motor Traffic Act, Licensing and Driver Responsibilities
You must know the legal framework that governs driving in Sri Lanka: the Motor Traffic Act and its regulations, licensing categories, vehicle documentation and the duties of a driver after a crash. Understand that driving a heavy vehicle requires the correct licence class and that driving without the proper class, or with a suspended or expired licence, is an offence.
450 words, about 2 min