One method to extend the range of transport carried out with electric commercial vehicles is the relay of semi-trailers, in which the load unit is quickly transferred between different tractor units. This technique is already used by some haulage companies with diesel trucks to keep shipments constantly on the move without exceeding drivers' driving and rest times. It could also prove crucial in overcoming the range limitations of electric trucks. The transport is managed via a telematic system.
This system is being developed by the German tech firm Mansio and Mercedes-Benz Trucks, who are adapting the old Pony Express model to modern technology. In the 19th century, this system enabled mail delivery from Missouri to California in just ten days through a relay of horses over 3,200 kilometres. In the experimental system being promoted by Mercedes-Benz Trucks and Mansio, the primary goal is not delivery speed but maximum efficiency in vehicle usage.
Each truck, once it has returned to the depot after handing over the load to another vehicle, can set off again, potentially with a new driver. This not only speeds up return on investment for transport companies but also improves drivers’ quality of life, allowing them to end their shifts at home rather than sleeping at rest areas. “The relay works with both diesel and electric trucks, but it’s only effective if journeys are perfectly coordinated. Neither vehicle should have to wait for the other. Ongoing synchronisation, based on real-time shared data, is essential,” explains Martin Gaissert, project manager at Mercedes-Benz Trucks.
This synchronisation is ensured by software developed by Mansio, which acts as an interface between the different IT systems of the companies involved. The shared information includes vehicle locations, estimated travel times, battery charge levels for electric trucks, planned routes and order data. This system can smoothly coordinate the meeting of vehicles, even from different companies, overcoming a limitation of existing relay operations that are typically restricted within individual fleets.
The pilot project, launched in spring 2025, involves the haulier Logistik Schmitt from Bietigheim, along with a logistics client. For six months, the two operators will run a daily round trip of around one thousand kilometres between the Daimler Buses plant in Mannheim and a supplier near Leipzig. At a designated midway point, an electric eActros 600 and a diesel Actros L will exchange semi-trailers before returning to their respective bases. The electric vehicle is charged at the Mannheim facility and at the Hermsdorfer Kreuz hub, where a charging park operated by Milence, an infrastructure consortium partly owned by Daimler Truck, is active.
