Impact Assessment: High Capacity Vehicles

In the United Kingdom (UK), the length of a goods carrying vehicle is limited to a maximum of 16.5m for a standard articulated vehicle and 18.75m for a draw-bar combination. In October 2011, the Department for Transport announced trials of extended length semi-trailers with the aim of investigating the impact of increasing the length of an articulated vehicle up to a new maximum of 18.55m, an increase of 2.05m.

A number of countries in the European Union (EU) have opted to either permit or trial vehicles that are substantially longer than those currently permitted or under trial in the UK, with the extension of length often accompanied by an increase in the maximum gross weight of the vehicle. The European Commission is currently undertaking a review of the EU Directive that governs the weights and dimensions of vehicles operating in the EU.

This study assesses the environmental, economic, safety and practical impacts of increasing the maximum length of vehicles in the UK to 25.25m, while maintaining the maximum gross weight at the current UK limit of 44 tonnes (with such a vehicle herein referred to as a ‘High Capacity Vehicle’ or ‘HCV’). The scope is limited to the consideration of 25.25m vehicle variants that are currently in use in the Netherlands.

An increase in vehicle length, without any corresponding increase in gross weight of the vehicle is of particular benefit to transporters of low density goods that regularly fill the cubic capacity of a vehicle without accessing its full weight carrying capacity. The costs of transport of low density goods, when measured on a per tonne or per tonne kilometre basis, are significantly higher than for more dense goods.

Analysis of UK road freight transport flows in this research suggests that there are significant opportunities for the use of HCVs for the carriage of low density goods. Such opportunities include;

Transport of full loads of lightweight goods in roll cage or palletised form;

Lightweight container transport; and;

Other niche operations.

The above opportunities are estimated to equate to an annual flow of approximately 1,425 million articulated vehicle kilometres, accounting for 15% of the total distance travelled by articulated vehicles.

Commodities that have greatest potential for use of HCVs are found to be Packaging, Perishable Foodstuffs, Non-perishable Foodstuffs, and Other Manufactured Goods.

At vehicle level, fuel consumption and carbon emissions of an HCV are greater than for a standard length vehicle, however, this report finds that when the additional carrying capacity of an HCV is considered, the fuel consumption and carbon emissions per unit of load decrease by between 11% and 19% (on a per pallet kilometre basis). Transport costs are found to decrease by approximately 19% on a per pallet kilometre basis.

The potential benefits of the use of HCVs within case study companies are explored in this research through detailed modelling of transport operations, focusing on organisations that carry large quantities of low density goods. This analysis finds that the total carbon emissions of these transport operations would reduce by up to 10%, and that total transport costs would fall by up to 12%, were HCVs to be integrated within transport operations alongside other fleet options. Percentage reductions would be greater if compared against large vehicle emissions / costs only – with reductions of up to 13% and 17% respectively. These results demonstrate the significant benefits to be gained by shippers of low density goods.

While most rail freight traffic is too heavy to make use of the volumetric carrying capacity of an HCV, this study finds that a maximum of 20% of rail intermodal / deep sea container traffic would be at risk of modal shift from rail to road. As rail freight has comparatively lower carbon emissions than road freight, modal shift would result in an increase in the emissions associated with transferring freight. This would partially offset the emissions savings from transfer of conventional road traffic to HCV, but, on balance, this study finds that there would be a significant net reduction in carbon emissions.

In the event that all identified low density road and rail freight traffic migrated to HCV transport, annual transport cost savings are estimated at £226 million, with total carbon emissions reducing by an estimated 96 thousand tonnes per annum. Use of HCVs would be likely to reduce the number of large goods carrying vehicles using the UK road network, with total distance travelled by large vehicles reducing by up to 4%, making a useful contribution to the relief of congestion.

A review of the evidence presented in a number of key reports and publications on the safety of longer vehicles and the actual experience of operation of such vehicles in the EU, finds that the introduction of HCVs that have been configured to comply with UK turning circle standards would have no significant impact on safety in terms of road traffic accidents. This is subject to the vehicles being purpose built to a suitable specification and incorporating advanced technological features including steer axles, advanced braking systems, stability technology and suitable visibility aids. Appropriate driver training is also critical.

Practical considerations will reduce the potential use of HCVs. HCVs can be configured to comply with currently applicable manoeuvrability standards but restrictions on usage on some parts of the road network would still be required (as is the case for conventional large vehicles). At some smaller transport origin and destination points, access to the site and operation on site may be problematic. The ability to decouple sections of the vehicle close to the delivery point and to transport each part separately can overcome such access issues.

It is estimated that practical constraints would limit HCV use to approximately 40% to 60% of the total opportunity and net economic and emissions benefits would reduce accordingly, however, substantial benefits would remain. At this level of use, annual transport savings would be between £90 million and £135 million, with a reduction in carbon emissions of between 38 thousand and 58 thousand tonnes per annum.

In summary, this study finds that permitting the use of HCVs in the UK under controlled conditions would reduce transport costs, has the potential to reduce carbon emissions and will not compromise the safety of road users. Practical constraints will limit application in some circumstances, but there is a significant opportunity to improve the efficiency and sustainability of freight transport and to achieve cost reduction in the transport of low density goods.