Blog: The Campaign against Longer Semitrailers


I was invited into the local BBC radio station last Monday to discuss the UK trial of longer semitrailers (LSTs).  I found myself debating a representative of Campaign for Better Transport, who the week before had released a blog and letter to the Department for Transport (DfT) entitled ‘Local authorities must be involved in longer lorry trial’  https://bettertransport.org.uk/blog/better-transport/longer-lorry-concerns.

The trial of LSTs has been running for 6 years and includes about 2000 trailers which are mostly 2.05m longer than conventional trailers – ie 15.65m instead of 13.6m.  The allowable gross vehicle weight (GVW) of the tractor-semitrailer combinations is the same as conventional UK articulated vehicles: 44t.  In order to negotiate the standard UK roundabout manoeuvre, the LSTs have some arrangement of command steer and/or self steer axles on their triaxle groups.  An independent organisation (Risk Solutions), generates a report on the trial every year for the DfT, based on compulsory vehicle logs and incident data reported by the operators https://www.gov.uk/government/publications/longer-semi-trailer-trial-evaluation-annual-report-2017.

  1. Use on Minor Roads

The Campaign’s central grievance is about exposure to these vehicles on minor roads:

“We do not believe that the trial is adequately assessing the impact of these longer lorries on local roads or involving local authorities, which manage minor roads which make up 97 per cent of the network. The latest report reveals that 38 per cent of the longer lorry journeys are off the motorway network and yet the majority of local authorities who will be responsible for dealing with the impact of these lorries once they leave the motorways, are unaware of the trial.”

The facts are a bit different to this.  Reproduced below is a figure from the 2017 summary report.  It shows the breakdown by distance travelled on Motorways, A-roads and Minor roads for the whole GB fleet of large articulated HGVs and the LST trial HGVs.

It is apparent that in 2017, 38% of LST mileage was indeed off the motorway network.  However, 36% of the mileage was on ‘A-roads’, which are major trunk routes, mostly managed by Highways England and only 2% of the mileage was on minor roads, maintained by local authorities.  The Campaign is being ‘selective’ with the facts.  The 38% of miles managed by local authorities that they mention was in fact 2%!

LST ExposureThe reason for this distribution of journeys is that these LSTS are used in an appropriate way: for trunking operations on the major road network from warehouse to warehouse and occasionally for re-stocking major ‘out of town’ supermarkets.  They almost never operate on the local urban and rural roads that The Campaign is fear-mongering about.

So what about the rest of The Campaign’s arguments?

  1. Road Damage and Fuel Consumption

Contrary to the Campaign’s claim that the LSTs do more damage to the roads and the environment (because they are larger), they actually do less damage.

“these bigger trucks result in lorries paying even less of the costs they impose on the economy and society with the taxpayer picking up the bill in terms of more road crashes, road damage, congestion and pollution”

The report shows that 7% fewer journeys are driven by LSTs to deliver the same amount of freight as the conventional vehicles they replace.  Since the axle load limits are the same, this translates to 7% less road damage; approximately 7% less fuel; and 7% less CO2 emissions than the conventional vehicles they replace.  The effect on traffic congestion is difficult to quantify – but having fewer lorries on the roads certainly does not increase traffic congestion.

  1. Safety

Government statistics show that existing sized heavy goods vehicles were almost seven times as likely as cars to be involved in fatal collisions on minor roads in 2016.”

This, of course, is the accident rate per vehicle, not per the accident rate per km travelled.   Since lorries travel approximately 10 times further than cars each year, they are significantly safer than cars per km travelled.  Furthermore, the report on the trial shows that the LSTs have been involved in approximately 70% fewer collisions per km than conventional articulated vehicles.  They have a much better safety record than the existing vehicles.  This is consistent with operation of high capacity vehicles all around the world – in Canada, Australia, South Africa, Brazil and Argentina, and throughout Europe – Scandinavia, Netherlands, Germany and Spain.  Why?  Because in all of these operations, great care is taken to ensure that the vehicles have the best inherent safety performance possible, are driven by the best drivers, only operate on suitable routes and are maintained to the highest standards.  This is how all high capacity vehicles should be run and the way to ensuring more efficient and safer (‘Better) transport.  The LST trial has proven that this approach works in the UK as well.

  1. Empty Running

The Campaign complains that:

“the trial shows that the longer lorries were only fully loaded for 37 per cent of their journeys in comparison with 36 per cent of existing sized lorries being fully loaded which is a negligible gain.”

The reality is that empty running in the UK HGV fleet is currently approximately 29%.  For the LSTs in the trial, empty running in 2016 was just 18%.  LSTs are running full much more often than conventional HGVs. Why is this?… The comparison fleet of conventional HGVs includes tankers, construction vehicles, etc, that always return home empty.  There are very few of these vehicle types in the LST population – so the empty running is less.

LSTs are not always fully loaded because they are only allowed a GVW of 44t. (This is because the Government gave-in to the anti-lorry lobby at the time of their introduction and did not allow a weight increase, despite the LSTs greater volumetric capacity.)  Consequently, when loaded with supermarket cages, these vehicles reach their mass limit before being fully loaded by volume.  Tesco, (the largest supermarket in the UK) has estimated that approx. half of their double deck trailer trips are not full to capacity due to weight constraints, corresponding to 90,000 trips per year.  “With an additional 4t of payload, Tesco alone could save 900,000 road miles and 1million kg of CO2 annually.”  (Nick Dunn, Head of Transport, Tesco: Representation to Minister of Transport, Jan 2016).

So what can we conclude from all of this?

  1. The longer semitrailer trial has been very successful.  The vehicles have an excellent safety record, low levels of empty-running and 7% less environmental impact (road damage, CO2 emissions) than the conventional fleet. These vehicles are performing very well.
  2. The LSTs are objectively ‘Better Transport’ than the conventional fleet, by every measure considered in the trial.
  3. The anti-lorry lobby groups will continue to be selective with their use of facts in order to persuade politicians and the general public against the use of cleaner, more productive, vehicles.

With the IPCC report last week calling for urgent decarbonisation of all sectors over the next 12 years to 2030, we can’t afford to ignore one of the most effective ways to reduce fuel consumption and emissions from road freight transport.  Higher capacity vehicles are essential to our future.  LSTs are a good start…

David Cebon
13/10/2018