32-metre-long, two standard semi-trailers and only one tractor: With the EcoDuo, German and Spanish companies want to make road freight transport more efficient and climate-friendly. After a year of field testing between Wolfsburg, Lehrte and Barcelona, the project consortium draws a positive balance – and now pushes for political policy decisions to enable regular operation.
A pilot with signaling impact
In September 2024, the Association of the Automotive Industry (VDA), Schmitz Cargobull, the Spanish logistics company Sesé, Kombiverkehr, Volkswagen Group Logistics and TÜV Rheinland started the pilot project in Lower Saxony. Since then, the EcoDuo vehicle combinations have, according to the companies, completed regular cycles to Barcelona and back for a year. The aim, according to the joint statement, was to test the everyday practicality of the unusually long tractor-trailer combinations in the pre- and post-haul of intermodal transport and to gather experience for a possible regular operation.
The EcoDuo consists of two standard semi-trailers connected by a dolly and pulled by only one tractor. The overall length is 31.70 meters, the permissible gross weight is 40 tons, in intermodal transport 44 tons. Thanks to ten axles, axle loads stay below the applicable limit values. For the pilot operation, exemptions under § 70 StVZO and § 29 Abs. 3 StVO applied.
Seamless connection to the rail
A key finding from the
trial: The EcoDuo can be loaded onto the rail without extra effort. According to the consortium's statement, the two semitrailers simply need to be decoupled before loading and reconnected after unloading. No additional technical adjustments are necessary. However, there must be sufficient space at intermodal terminals for maneuvering and staging, as well as adequately sized maneuvering zones.
According to the project leaders, the challenge lies less in on-site maneuvering, and more in the question of whether the EcoDuo tractor-trailers can enter and exit the terminals as a whole. Where this is not possible, they would have to be coupled or decoupled before entering the site.
During the test phase, the terminal operators handled the dolly themselves: they parked it on the premises and reused it in the next cycle. This solution was pragmatic, but should be reviewed regionally depending on the site.
“The results of the pilot project convincingly demonstrate that the concept can be seamlessly integrated into existing structures and is convincing both ecologically and economically,” summarizes VDA managing director Andreas Rade.
Efficiency, climate protection and driver shortage
The project team cites several advantages. By carrying two standard trailers with a single tractor, transport capacity per trip increases, reducing trips and thus emissions. At the same time, freight forwarders could mitigate the acute driver shortage because fewer drivers are needed
for the same transport volume.
The combination is particularly suitable for volume transports, for example plastic parts for automotive production, textiles or parcels. The payload is currently a maximum of nine tons per trailer, because the permissible gross weight in Germany is limited to 44 tons. According to the project partners, technically much higher weights could be realized, but current legislation limits this.
In contrast to previous long-truck concepts, the EcoDuo is intermodally connectable, the partners emphasize. While conventional long trucks cannot readily be loaded onto the rail, the EcoDuo trailers meet the usual requirements for intermodal transport.
Legal hurdles for regular operation
For the combination to roll in everyday use, legal provisions must be adjusted. According to the consortium, the regulation on exemptions from road traffic regulations for vehicles and vehicle combinations with overlength is to be expanded with a new vehicle type “Type 6.” This would allow truck-trailer combinations up to 32 meters in length to operate on a specially defined positive network. This network is intended to include primarily intermodal transport locations and thus secure integration into existing transport chains.
The project partners see the EcoDuo mainly in hub-to-hub traffic and in the inbound and outbound flows of intermodal transport. They do not foresee any concerns about operational safety. The EcoDuo would meet all technical standards, including the
requirements for long trucks, and would not exceed permissible axle loads or total weights.
The industry is also looking abroad: In Spain, around 1,000 EcoDuo vehicles are already in operation, and they are also in use in Scandinavia. There, higher permissible total weights apply, which makes operation economically more attractive. How deployment in Germany will develop is not yet foreseeable, according to the project leaders.
Outlook for the industry
After completing the scientific evaluation by TÜV Rheinland, the participants want to officially approve the EcoDuo in Germany. In Spain and Scandinavia, the concept is already established. For logistics companies, this opens the chance to move more loading volume per vehicle, reduce CO2 emissions, and better utilize scarce driver resources.
However, much depends on future weight regulations. The project partners emphasize that the current limit of 44 tons restricts deployment options. Higher permissible total weights could significantly increase the economic significance of the concept.
The coming months will likely show whether policymakers and authorities create the legal framework for the new vehicle type. For freight forwarders and fleet managers, this could mean getting ahead in route planning, terminal logistics, and driver dispatch to prepare for the possible deployment of such combinations. Those active in intermodal transport could particularly benefit from the EcoDuo – provided that the infrastructure is adapted and the legal
