The first Super Ecocombi (SEC) is due to undergo its final tests at the RDW test track in Lelystad in the coming weeks. If it meets the required safety conditions and exemptions are granted, the combination will enter public roads for a pre-test on the Rotterdam–Moerdijk–Venlo corridor.
However, the conditions for that test have already been tightened. The maximum permitted weight has been reduced from 72 tonnes to 64 tonnes, while the RDW has also called for the vehicle to be accompanied by transport escorts for more of the test period than originally envisaged.
The SEC consists of a tractor, two 13.6-metre semi-trailers and a dolly, giving the combination a maximum length of around 32 metres. According to Dutch transport association TLN, one SEC can carry roughly the same volume as two conventional 16.5-metre tractor-semitrailer combinations.
Supporters argue that this could reduce the number of vehicles and drivers required to move a given amount of freight, while also cutting emissions per unit of cargo.
Cameras to monitor other road users
The public-road exercise will initially be a pre-test rather than a commercial operation. It will take place at different times of day along the Rotterdam–Moerdijk–Venlo route and will not carry normal commercial cargo.
The combination will be equipped with 360-degree cameras, allowing researchers to study both how the vehicle behaves on the road and how other road users react to its unusual length. Its performance is also expected to be compared with that of a conventional tractor-semitrailer combination.
One issue still being discussed is the use of escorts. The original arrangement was for the SEC to be accompanied for its first journey on safety grounds. TLN says the RDW has subsequently decided that transport escorts should remain in place for several days because the submitted risk analysis did not provide sufficient assurances for fully unescorted operation.
TLN argues that eventually allowing the vehicle to travel without an escort is important if researchers are to obtain representative data on its interaction with normal traffic. Discussions are therefore continuing over gradually reducing the level of accompaniment during the pre-test.
Pilot planned for 2027
If the pre-test is successful, the project partners intend to move to a wider pilot involving several Super Ecocombis around the summer of 2027. Current plans envisage two weight categories. A combination of up to 72 tonnes would require a 6×2 tractor, while a lighter version of up to 57.5 tonnes could operate with a 4×2 tractor. The vehicles could operate on several routes on the Dutch main-road network, although those corridors have yet to be selected.
The vehicle being prepared for the first test uses a 6×2 tractor with a steered leading axle, followed by a three-axle first trailer with a lift axle and steered rear axle, a two-axle dolly with a self-steering axle and a rigid three-axle rear trailer.
Years of delays
The latest timetable marks another step in a project that has been under discussion since 2019 and has encountered repeated delays. In 2025, TLN expected the pre-test to begin before the end of that year, with a small pilot involving between five and ten combinations following during 2026. The public-road pre-test is now expected in autumn 2026, while the wider pilot has shifted to around summer 2027.
An earlier attempt stalled even more dramatically. In 2022, the Ministry of Infrastructure and Water Management stopped plans for a pilot after concerns were raised about infrastructure and road safety. The RDW had previously declined to grant an exemption for the configuration being considered after tests and research indicated that safety on parts of the secondary road network could not be sufficiently guaranteed.
The project was subsequently revived with a revised testing programme and a new set of safety requirements. The SEC now being prepared for the Dutch trial has, however, already had a brief taste of public-road operation. At the end of May it was used in a one-day practical test in the port area of Ghent, Belgium. TLN says that test was completed successfully.
Longer combinations of this type, generally referred to internationally as EMS2 vehicles, are already in operation in countries including Sweden, Finland, Denmark and Spain, while Germany is also conducting trials.
For the Netherlands, the coming pre-test will determine whether the concept can finally progress from years of closed-site testing and regulatory discussions to regular trials on the public road.
