The Freight Transport Association (FTA) is calling for the UK government to make use of longer semi-trailers (LSTs) a permanent fixture on the UK’s roads following the successful outcome of its trial. However, the trial has been extended until 2027.

Released on 2 March, 2020, the Department for Transport (DfT) funded study demonstrates that use of these vehicles continues to have a significant impact on the reduction of carbon emissions and road congestion across the UK; they have also been found to be safe for both the driver and other road users.

Phil Lloyd, Head of Engineering & Vehicle Standards Policy at FTA, said: “The UK’s roads are congested and carbon emissions from road transport remain too high; with LSTs able to carry more goods per journey than traditional HGVs, they present an efficient and environmentally-prudent method of freight transportation.”

DfT has been running a trial of the operation of LSTs on roads for the past seven years. Over this period, use of LSTs resulted in 365,000 fewer journeys taking place. This reduction in mileage has led to the saving of 37,000 tonnes of Carbon Dioxide (CO2e) and 187 tonnes of Nitrogen Oxide (NOx). Additionally, LSTs had 55% fewer collisions compared to the HGV average.

The Department for Transport began a trial of longer semi-trailers for articulated goods vehicles in January 2012. The trial involves longer semi-trailers of 14.6 metres and 15.65 metres in length (17.5 metres and 18.55 metres total vehicle lengths respectively). The trailers must operate within the UK’s existing domestic weight limit (44 tonnes for vehicles of 6 axles).

The trial was originally scheduled to run for a maximum of 10 years from 2012 with a total allocation available of 1,800. In 2017 the government agreed to increase the number of LSTs by an additional 1,000 and to extend the trial by 5 years to 2027. This increase will take the number of LSTs from 1,800 to approximately 2,800.