In January 2012, the Department for Transport (DfT) introduced a trial of longer semi-trailers (LST) for articulated lorries. Now, in 2021, the ongoing trial involves 228 voluntary participants and 2,600 LSTs in total.

With the study coming to an earlier end than planned, we wanted to assess both the aims and the findings of this to see what the future holds for freight.

A Detailed Overview of the Trial

Longer semi-trailers are both 14.6 metres and 15.65 metres in length and operate within the UK’s domestic weight limit of 44 tonnes. Originally set to run for a maximum of 10 years, the trial was led as a response to the haulage industry requesting the UK to adopt the 25.25m European Modular System (EMS).

As our roads are not suitable for EMS vehicles, the trial was a negotiation to still see if the use of larger goods carrying vehicles could provide the same benefits that this system did in countries such as Scandinavia and the Netherlands. A total of 1,800 LSTs were available for the trial and the study has been running for years.

What Are the Benefits of Longer Semi-Trailers?

Due to their bigger dimensions, LSTs reduce the number of lorry journeys significantly as they can carry the same amount of freight in fewer vehicles. This, in turn, provides distinctive environmental benefits as well as economic advantages.

According to, up to the end of 2019 the trial results indicated that:

  • on average, the use of LSTs reduced journey numbers by 1 in 12, with more than 54 million vehicle kilometres saved
  • 48,000 tonnes of CO2(e) and 241 tonnes of NOx have been saved
  • on a per kilometre basis LSTs have been involved in about 53% fewer personal injury collisions and casualties than the GB articulated heavy goods vehicle (HGV) average

The Future of Green Logistics & Longer Semi-Trailers

In November 2020, it was announced that the trial had reached a point where further research was unnecessary and remaining safety issues could only be answered outside of trial settings.

DfT’s preference would be for unrestricted access to LSTs due to the contribution they have had to carbon emissions. Regarding the safety issues, extra regulatory measures should also be put into place if this was the case.

In other news, the government may now be launching trials of heavier 48 tonne freight so more cargo can be shipped from road-only to rail transportation. It’s great to see more trials and changes being made to help increase sustainability across the logistics industry and at Cross Country Carriers, we are always aiming to improve our carbon footprint where possible. Contact us today to find out more about us and what we can do for you.

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