Term and legal definition of trailer
A trailer, in the legal sense, is a non-self-propelled vehicle intended to be attached to a motor vehicle and used to transport people or goods. The legal definition and structure of the term “trailer” can be found in various national legal provisions, particularly in road traffic law, registration law, as well as in numerous regulations and technical standards.
Statutory foundations
In Germany, the term “trailer” is primarily regulated by the Road Traffic Act (StVG), Road Traffic Regulations (StVO), Road Traffic Licensing Regulations (StVZO), and the Road Vehicle Registration Regulation (FZV), especially in § 2 No. 2 FZV and § 32 StVZO. The central definition is as follows:
“Trailers are vehicles designed for use on roads, which are connected to another vehicle and are not self-propelled.”
(§ 2 No. 2 FZV)
This definition also elaborates various subtypes and distinctions in detail.
Types of trailers in a legal sense
Motor vehicle trailers
In road traffic law, trailers attached to all types of motor vehicles are divided into:
- Light trailers: Trailers with a permissible total weight of no more than 750 kg (§ 42 para. 1 StVZO).
- Heavy trailers: Trailers with a permissible total weight of more than 750 kg.
- Trailers with their own official license plate (§ 10 FZV).
- Semi-trailers: A trailer which rests primarily on the towing motor vehicle and is pulled by it (§ 2 No. 3 FZV).
- Semi-trailer: This refers to a special form of trailer in which a significant part of the mass is transmitted onto the towing vehicle.
Non-motor vehicle trailers
The legal term ‘trailer’ can also refer to non-motorized vehicles such as bicycles (bicycle trailers) or animal-drawn vehicles, as long as they participate in road traffic.
Exceptions and special cases
According to § 18 para. 2 FZV, agricultural or forestry machinery towed on axles, provided their speed does not exceed 25 km/h, are not considered trailers.
Registration and identification of trailers
Registration requirement
The fundamental registration requirement for trailers is set out in § 3 para. 1 FZV, with exceptions for certain “attached working equipment” (§ 3 para. 2 FZV) as well as certain agricultural and forestry trailers (§ 3 para. 2 No. 2 FZV).
License plates and certificates
Regulations on license plates can be found in the Vehicle Registration Ordinance (FZV). Trailers are registered independently and receive their own official license plate.
For certain light trailers, a so-called “exchange license plate” or a “red license plate” (for instance, for inspection, test, or transfer drives according to § 16 FZV) is permitted.
Towing capacity and towing combinations
The permissible towing capacity, i.e., the maximum admissible weight of the trailer that a towing vehicle may pull, is indicated in the registration certificates (Part I and II) of the motor vehicle and is governed by technical as well as statutory provisions (in particular § 42 StVZO).
The permissible maximum length of the vehicle combination is also regulated: For car-trailer combinations, this is generally a maximum of 18.75 meters (§ 32 StVZO).
Type approval and technical requirements
Technical requirements
Trailers are subject to extensive technical requirements, which are regulated in the Road Traffic Licensing Regulations (StVZO) and supplementary statutory regulations. In particular, these include provisions regarding:
- Lighting and signaling devices (§§ 49a ff. StVZO)
- Brakes (§ 41 StVZO)
- Coupling devices and breakaway cable (§ 43 StVZO)
- Axle loads and chassis
Commissioning is generally only permitted with a valid type approval (§ 19 para. 1 StVZO).
Inspection obligations and main inspection
Trailers with their own official license plate are regularly subject to the main inspection (HU). The inspection intervals are set out in Appendix VIII of the StVZO and are generally two years.
Duties and liability in connection with trailers
Owner and driver obligations
The owner of the trailer is responsible for proper registration, compliance with technical requirements, and valid insurance coverage. Drivers of a combination must ensure that:
- the combination does not exceed permissible dimensions and weights,
- the trailer is properly attached to the towing vehicle,
- cargo is secured in accordance with legal requirements (see § 22 StVO).
Insurance obligation
For trailers with their own official license plate, a separate liability insurance obligation exists in accordance with the Compulsory Insurance Act (PflVG) (§ 1 PflVG).
Liability in case of damage
In the event of an accident involving a combination, the liability regime of §§ 7 ff. StVG applies. Special rule: For damages caused by the trailer, the owner of the trailer is primarily liable, under certain circumstances also the owner of the towing motor vehicle.
Tax law aspects
Trailers are subject to motor vehicle tax in accordance with the Motor Vehicle Tax Act (KraftStG). Tax exemptions may apply for certain agricultural and forestry trailers (§ 3 No. 7 KraftStG) as well as trailers with seasonal use.
Driving license regulations for driving combinations with trailers
Specific driving license categories apply for driving vehicles with trailers, as prescribed by the Driving License Directive and the Driving License Regulation (FeV):
- Class B: Cars with trailers up to 750 kg or more than 750 kg where the total permissible mass of the combination does not exceed 3,500 kg.
- Class BE: Combinations with trailers up to 3,500 kg.
- Class B96: Permits towing heavier trailers in private use after a special training.
Stricter rules apply to commercially used trailers.
International and European law
The recognition and use of trailers in cross-border traffic are governed by international agreements, particularly the Vienna Convention on Road Traffic of 8 November 1968, as well as relevant EU Directives, such as Directive 2007/46/EC on vehicle type approval.
Literature and further legal regulations
- Road Traffic Regulations (StVO)
- Road Traffic Act (StVG)
- Road Traffic Licensing Regulations (StVZO)
- Vehicle Registration Regulation (FZV)
- Compulsory Insurance Act (PflVG)
- Motor Vehicle Tax Act (KraftStG)
- Driving License Regulation (FeV)
- Regulation (EC) No. 2007/46/EC (Type Approval)
This article provides a comprehensive overview of the legal foundations, types, registration requirements, technical regulations, obligations, liability aspects, and international perspectives regarding the term “trailer” in road traffic law.
Frequently asked questions
Which driving license categories are required for driving with trailers in Germany?
In order to tow a trailer on public roads in Germany, the appropriate driving license class is decisive. The basic license for towing a trailer is the car driver’s license Class B, which allows drivers to operate a vehicle combination provided the permitted total mass of the trailer does not exceed 750 kilograms. In certain cases, trailers over 750 kg are also allowed, provided the total mass of the towing vehicle and trailer together does not exceed 3,500 kg. For heavier trailers, the extension B96 is required, allowing combinations up to 4,250 kg – this only requires special training, not an exam. Those who wish to drive combinations with trailers over 750 kg and a total mass up to 7,000 kg need a Class BE license. For even heavier combinations, such as those used in commercial transport, Classes C1E or CE are required. It is advisable always to check the entries in the vehicle registration documents as well as statutory provisions, since exceeding the limits may result not only in fines but also in loss of insurance coverage.
Must trailers be registered separately in Germany?
Yes, in Germany trailers must be individually registered. This means every trailer is given its own official license plate and its own registration certificates Part I and II. Registration is carried out by the relevant registration authority, for which, among other things, the certificate of conformity (COC paper) or an expert opinion from a technical service, a valid main inspection (for trailers subject to registration), a valid identity card, and proof of current liability insurance must be presented. There are exceptions for registration-exempt trailers, such as agricultural or forestry working implements, but these are also subject to certain labeling requirements. If trailers are used in public road traffic without registration, fines and further legal consequences may follow.
Is there an insurance obligation for trailers?
Yes, according to § 1 of the Compulsory Insurance Act (PflVG), there is generally an insurance requirement in Germany for trailers subject to registration. The insurance obligation extends to motor vehicle liability insurance, covering damages to third parties caused by the trailer. The insurance policy must be presented when the trailer is registered at the registration authority. For certain trailers, such as caravans or refrigerated trailers, comprehensive insurance is also recommended to cover own trailer damages from theft, fire, natural events, or vandalism. Registration-exempt trailers, such as certain agricultural trailers, usually do not need their own insurance as long as they are operated together with an insured towing vehicle. However, the insurance and liability aspects must be carefully considered in case of damage.
What special requirements apply to the lighting and marking of trailers?
The Road Traffic Licensing Regulations (StVZO) contain detailed rules regarding the lighting and marking of trailers. This includes mandatory lighting equipment such as tail lights, brake lights, indicators, a rear fog lamp (for trailers from 750 kg upwards), red reflectors, a white license plate illumination, and, for certain widths, marker lights. For adequate safety in road traffic, it is also important that reflectors and lighting elements are always functional and clean; regular checks are recommended and are part of the main inspection. Even registration-exempt trailers, such as bicycle racks or small transport trailers, are subject to lighting regulations that must be complied with by the manufacturer. Attaching warning panels may be required for loads that stick out (§ 22 StVO). Violations not only lead to fines, but may also negatively affect liability in the event of an accident.
What regulations apply to load securing on trailers?
According to § 22 StVO, loads and equipment on trailers must be secured in such a way that, even during sudden driving maneuvers, such as sharp braking or emergency swerves, they cannot slide, tip over, roll around, fall off, or create avoidable noise. Recognized securing methods include the use of lashing straps, nets, tarpaulins, or special securing systems. Special rules apply to hazardous goods transport and for over-width or over-length (in these cases, special marking and possibly a permit are required). Violations of load securing obligations can result in fines, points on your record in Flensburg, and, in case of an accident, shared liability or even criminal prosecution. Responsibility for checking load security lies with the driver – and for commercial transport, also with the loader.
At what intervals must trailers undergo the main inspection?
The main inspection requirement for trailers is regulated in § 29 StVZO. Basically, braked trailers and caravans must undergo a main inspection (HU) every two years, while for unbraked small trailers, which are often used privately, a 24-month interval usually applies. New vehicles must undergo their first main inspection 36 months after initial registration; thereafter, the usual two-year interval applies. In commercial use or with special trailer types, such as those transporting people, different intervals may be prescribed. During the main inspection, chassis, lighting systems, tires, brakes, and safety equipment are checked, among other things. Failing to attend or pass the main inspection means the trailer may no longer be used on public roads and may also lead to fines.
