Campaigners have criticised a new report that claims that longer semi-trailers (LSTs) can reduce congestion, pollution and collisions.
The report, five years into a 15-year trial of the 2.05m longer lorries on UK roads, estimates that the average percentage distance saving from using LSTs was around 5% to the end of 2016, equivalent to one in every 19 journeys.
It adds that the most efficient LST operations are saving up to one in every nine journeys.
The report says that while the 5% average saving in distance and journeys provides a rough proxy for all emissions savings, other factors will play a part. It recommends that the Department for Transport (DfT) includes a preliminary assessment of environmental impacts in the next phase of work on the trial.
It states that in the trial, the incident rate for LSTs has been lower than for other trailers but acknowledges that this may be distorted by a number of factors, including that operators taking part provide special driver training.
The report, compiled by Risk Solutions and published by the DfT, describes the trial as ‘probably the most comprehensive data collection process that DfT has ever conducted for a trial of new equipment’.
However, campaign group Freight on Rail said the report is based on flawed data and incorrect assumptions and ignores important safety factors.
It said the report used ‘a flawed assumption that increasing lorry sizes will result in fewer, better loaded trucks on the roads when there is simply no evidence to show this is achievable once the longer lorries are in general circulation’.
Philippa Edmunds, Freight on Rail manager, said: ‘Despite what the Department for Transport claims, longer semi-trailers are not the answer to reducing collisions, congestion or pollution and are actually more dangerous than standard HGVs on urban and town centre roads, because of their 7ft tail swing and extended blind spot.’