The work in this commission aimed to build on the outputs of a previous UK study (Knight, et al., 2008) that aimed to quantify the likely effects if LHVs were to be fully permitted in the UK. Our study updated that in the light of recent experience gained in trials across the world, especially in Europe, and developments in vehicle technology. The 2008 study concluded that significant economic benefits would arise from implementing LHVs, as well as casualty reductions and reduced infrastructure maintenance.
However, the 2008 report also identified concerns associated with the constraints of UK and EU law on how the vehicles could be implemented in the UK and the availability of parking facilities. Most importantly, it identified a risk that modal shift from rail could be of sufficient magnitude to cause a net increase in emissions. After the completion of the 2008 report, the Government decided that 60 tonne, 25.25m LHVs would not be permitted for the foreseeable future, but that further investigation of longer semi-trailers would be undertaken (ultimately leading to the successful 10 year trial).
During the updated study, led by WSP in 2021/22, we have found that there is now considerably more experience in the use of these vehicles around the world, but particularly in Europe. Those already trialling/deploying them, in a variety of different countries, now have 14 years more experience of the practicalities of their operation and impacts.
Australia and Canada are seen as the pioneers of the use of LHVs but many countries around the world are now following a similar concept. This includes ten EU countries that have either legalised the use of LHVs or are engaged in some form of trial of their use.
What are the benefits of LHV’s?
The basic premise is that 3 standard HGVs are replaced by 2 LHVs, with an improvement in efficiency leading to fewer vehicle kms travelled, reduced emissions, reduced operating costs, reduced demand for HGV drivers etc.
Estimated benefits defined in other countries include.
- Australia: Between $8bn and $20bn and 5.9 million tonnes of diesel saved.
- Sweden: 6% of diesel consumption saved.
- South Africa: 22% reduction in vehicle kms travelled.
- Canada: Up to 30% reduction in CO2 per tonne km.
The question then remains - can these benefits be achieved in UK conditions? Something that should be properly measured in a trial, once a trial has been defined that can maintain standards of safety and infrastructure protection.
What are the key questions a trial must answer?
The study and associated stakeholder engagement suggested that there are several questions to answer during a trial, including.
- Is there sufficient demand to justify a trial?
- What emissions impacts are expected?
- Can highway structures sustain the vertical loads imposed?
- Will LHVs pose increased risk to highway structures from collisions?
- What will the effect be on modal split?
- How much of the road network can be safely accessed by LHVs?
- What needs to be done to ensure drivers are competent with LHVs?
- What are the casualty risks & appropriate mitigations & approval standards?
Whilst identifying these risks associated with their use, we also found examples of a range of methods used in different countries to mitigate those risks.
From this, a framework can be developed within which we can explore a range of approaches, that could potentially be taken into a trial on UK roads, based on different mechanisms to manage the primary sources of risk by defining different permutations of:
- Vehicle configurations permitted.
- Vehicle performance required.
- Network access control and compliance.
- Degree of monitoring.
So, the overseas case studies appear encouraging enough to warrant further work to determine whether LHVs can be safely trialled on GB roads, however until more evidence is accumulated a ‘do nothing’ option cannot be discounted.
Download the full report from the Department for Transport website.
Jason Smallwood, Technical Director Freight Transport, has over 25 years in the Freight and Logistics industry.
The views expressed are the opinions of subject matter experts and do not necessarily reflect those of WSP.