New technical and traffic requirements for euro-modular combinations

On 21 October, the Directorate-General for Traffic (hereinafter DGT) published a new resolution establishing the technical requirements and specific traffic conditions that Euro-modular vehicle combinations must meet in order to travel on Spanish roads. The resolution has been in force since 23 October 2025, coinciding with the entry into force of the General Regulations of Vehicles, which, among others, regulate the new maximum mass values.

Types of vehicles that can be used in Euro-modular configuration

Only modules corresponding to the following types of vehicles may form part of a Euro-modular combination:

(1) Only machines intended for goods transport services are permitted.

Power and type approval requirements for the towing vehicle

The towing vehicle is subject to strict weight and power requirements. Firstly, the towing vehicle must be approved for a maximum gross weight of 72 tonnes and have a MOT certificate with a technically permissible maximum gross weight greater than the total laden weight of the combination in circulation. If the type approval for the maximum gross combination weight is less than 72 tonnes, this value shall be the maximum total weight limit for the combination of which the motor vehicle may form part.

Secondly, the towing vehicle must be equipped with a coupling device that is capable of ensuring the maximum mass of the combination and that is approved in accordance with Regulation No. 55 of the UN/ECE.

Thirdly, vehicles within the O₄ category acting as intermediaries must be approved as tow trucks. Vehicles already registered that do not have towing capacity must be modified to comply with this requirement.

Fourthly, both the motor vehicle and the towing vehicles in category O₄ must have the appropriate electrical, pneumatic and mechanical equipment for towing.

Fifthly and finally, the towing vehicle must have a minimum power of 5 kW per tonne of maximum laden mass of the Euro-modular combination. However, this power shall be increased by 1 kW per tonne when the combination exceeds 42 tonnes and travels on sections with gradients equal to or greater than 5% and 1 km in length. The owner of the motor vehicle must ensure that it can start on these ramps, even when the road surface is wet.

Key technical requirements for safety

The combination and its modules must meet the following technical safety requirements relating to field of vision, signalling, warning or prevention of dangerous situations:

• Air suspension or equivalent on the drive axles
• Mirrors or blind spot detectors
• Lane departure warning system or lane keeping assistance
• Emergency braking system capable of automatically detecting a dangerous situation and activating deceleration to avoid or mitigate collisions
• Electronic stability control system

Specific traffic conditions

Finally, the Resolution details a series of specific traffic conditions that directly affect the daily operation of the aforementioned vehicles, as they impose mandatory requirements for lighting, signalling, overtaking restrictions, speed and traffic, and operational suspensions in adverse weather conditions.

• Lights: when driving on conventional roads with a single carriageway for both directions of traffic, it is mandatory to have dipped headlights or daytime running lights on.
• Signalling: the combination must be equipped with two V-2 light signals or amber flashing devices located at the upper front and rear ends, the V-6 long vehicle signal, the V-23 environmental signalling badge, and all other mandatory signals for goods transport.
• Overtaking restrictions: on single carriageway roads for both directions, they may not invade the lanes intended for the opposite direction to overtake vehicles travelling at more than 45 km/h. In addition, overtaking is prohibited on ramps with gradients of 4% or more, on viaducts longer than 150 metres and in tunnels.
• Speed restrictions: the maximum speed shall be that established in Article 48 of the General Traffic Regulations for vehicles with a maximum authorised mass exceeding 3,500 kg.
• Traffic restrictions: those published by the DGT for goods transport combinations exceeding 7,500 kg.
• Suspension of traffic on conventional single carriageway roads for both directions of traffic when weather conditions pose a risk to traffic: driving is prohibited when visibility is less than 150 metres ahead and behind, or when the State Meteorological Agency (AEMET) has activated extreme risk warnings: specifically, red level for wind, or orange level if the vehicle is travelling without a load; or the orange or red level for rain or snow, regardless of whether the vehicle is travelling with or without a load.
• Stowage of cargo: cargo must be stowed correctly to prevent any movement that could compromise the stability of the vehicle while in motion.

Finally, it should be noted that on 22 October, the day after the resolution establishing the technical requirements and specific driving conditions that Euro-modular vehicle combinations must meet in order to travel on Spanish roads, the DGT issued a new resolution establishing the network of routes suitable for Euro-modular vehicle combinations in Spain. The document details the specific roads, listed in Annex I and organised by autonomous communities, on which these large vehicles are authorised to travel. In addition to the defined sections, the regulations allow a maximum distance of 10 kilometres on roads not included in the network to connect to the main network or access a destination, always under the responsibility of the driver to verify the viability of the route.

The DGT’s resolution of 21 October, in force since 23 October 2025, marks an important regulatory change for Euro-modular combinations in Spain. The technical and traffic requirements it establishes include strict conditions on power, active safety and operational restrictions that seek to ensure the safety and efficient integration of these higher-capacity vehicles into the road network. With all these measures and the new network of routes suitable for Euro-modular combinations, the transport sector must now rigorously adapt to the new regulations in order to take advantage of the logistical benefits of these vehicles, while maintaining safety as a priority.