The Department for Transport this week released the latest findings of its long-term study into the use of longer semi-trailers (LSTs) on UK roads.
The in-depth, nationwide trial has been running for seven years and aims to establish whether the use of longer semi-trailers can bring about anticipated environmental and economic benefits.
LSTs are up to 2.05 metres longer than the current standard semi-trailers on our roads (15.65 metres instead of 13.6 metres).
While the trailers are longer than existing HGV trailers, they cannot be heavier. The total weight of the trailer, the goods and the tractor unit must still be within the UK domestic weight limit of 44 tonnes. They must also pass the turning circle test applied to the existing 13.6 metre trailers. To achieve this, LSTs usually have a steering rear axle.
The latest results released by the DfT are impressive.
They show that over this time the use of LSTs has resulted in 365,000 fewer journeys being made, saving an estimated 37,000 tonnes of carbon dioxide (CO2) and 187 tonnes of nitrogen oxide (NOx).
There’s also a significant economic benefit to operators, who are able to make big savings by delivering more goods in fewer journeys.
Additionally, LSTs had 55% fewer collisions compared to the HGV average.
But despite these findings, the trial is set to run until 2027, meaning the vast majority of hauliers are at least seven years away from being able to capitalise on the potential benefits.
And this week the Freight Transport Association (FTA) called on government to accelerate its timeframe, saying a failure to do so is holding businesses back.
It believes there’s already enough evidence in favour of LSTs to justify the government making them a permanent fixture on our roads.
Phil Lloyd, Head of Engineering & Vehicle Standards Policy at FTA, said, “Failure to make LSTs permanent is holding back an opportunity to significantly reduce carbon emissions. After all, the benefits LSTs provide to both the environment and the economy have been made evident in the government’s study.
“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.
“The quantity of freight that needs to be moved is relatively fixed – if we can move the same amount with fewer journeys, the better for the environment, the economy and other road users.”