Vehicle Coupling, Towing and Combination Safety
Core Concepts
Towing and coupling require understanding of weight limits, hitch types, and stability. In Bulgaria, the maximum towable mass depends on the towing vehicle's specifications and the driver's licence category (B licence allows trailer up to 750 kg, or more if combined weight ≤3500 kg). For trailers over 750 kg, a BE licence is needed. The coupling must be secure: use a proper hitch, safety cables, and check lights. Towing speed limits are lower: 70 km/h outside built-up areas and 50 km/h in built-up areas unless otherwise posted. Overloading or improper loading can cause snaking; load heavy items over the axle.
Traps in Questions
- Licence categories: Questions often test whether a B licence covers a specific combination. Remember: B allows trailer up to 750 kg, or trailer over 750 kg only if the combined weight of car and trailer does not exceed 3500 kg.
- Speed limits when towing: Many candidates forget that towing reduces speed limits.
- Safety chains: Must be crossed under the drawbar to catch the trailer if it detaches.
- Braking systems: Trailers over 750 kg must have an overrun brake or inertia brake.
Worked Example
You have a B licence and a car with maximum permissible mass 2000 kg. You want to tow a trailer with maximum permissible mass 1500 kg. The combined weight is 3500 kg, so it is allowed with a B licence, provided the car's towing capacity is at least 1500 kg. If the trailer were 1600 kg, combined weight would be 3600 kg, requiring a BE licence.
Rule of Thumb
When towing, reduce speed and increase following distance. A good rule: double your normal following distance. Check coupling and lights before every trip.