Truck weights and dimensions: more cargo, lower costs, less road wear

The European Commission proposed to review the Weights and Dimensions (W&D) directive in July 2023. By setting vehicle weight and length limits, the W&D directive is critical to support the industrial transition to zero-emission vehicles (ZEVs). Currently, the W&D directive allows ZEV combinations to weigh up to 2 additional tonnes compared to diesel trucks, while both share the same driving axle limit.

Current total weight and axle limits can lead to payload losses in some use cases, at least in the short and medium term, thereby penalising ZEVs. The 2-tonne weight allowance is not always sufficient to compensate for the added weight of some zero-emission models in long-distance trucking, therefore delaying their adoption. Additionally, a ZEV may reach the 11.50-tonne driving axle limit before fully utilising the 2-tonne additional weight allowance for the entire vehicle (i.e. before reaching the permitted total weight of 42 tonnes).

This can happen because battery packs are typically mounted along the chassis, adding extra weight to the driving axle. As a result, part of the 2-tonne allowance remains unusable, placing ZEVs at a payload disadvantage compared to diesel trucks. To tackle payload issues, the Commission proposed to increase the weight allowance for ZEVs from 2 to 4 tonnes, raising their total permissible weight to 44 tonnes, alongside an increase of their driving axle weight limit from 11.50 to 12.50 tonnes.

However, high axle weights can have an adverse impact on road infrastructure, and this 1-tonne increase in the driving axle weight has become one of the most contested elements in the political discussions. A year and a half after the proposal came out, EU Member States have yet to reach a common position. A new consultancy report[1] carried out by the consultancies Apollo Vehicle Safety & Research Driven Solutions outlines how the W&D review can support the transition to ZEVs while safeguarding Europe's roads and bridges.

Apollo Vehicle Safety examined possible alternative weight increases that would ensure a level playing field for ZEVs while minimising any negative effects on Europe's road infrastructure. The analysis quantifies the resulting road infrastructure costs due to the changes in vehicle and axle weights for three example countries (Germany, Poland and Romania) and projects those for the timeframe 2025 - 2040 based on the expected ZEV sales and fleet uptake in each of those markets. Research Driven Solution assessed ZEVs' impact on several bridge forms and lengths. Slightly reducing the proposed weight allowances for 5-axle combinations would ensure that most ZEVs currently on the market can achieve payload parity with 40-tonne diesel trucks.

Costs for Germany's road network would rise by just 1.41% compared to the current situation, saving EUR400 million compared to the Commission proposal over 2025 - 2040. In Poland and Romania, the increase could be limited to 0.72% each, with savings of EUR20 million each compared to the proposal. Shifting more of Europe's trucking fleet to an increased share of 6-axle combinations would significantly decrease road infrastructure costs compared not only to the Commission proposal, but also to current W&D rules. Germany alone would save EUR2.67 billion, while Poland and Romania EUR150 million each.

Delays in reaching an agreement threaten the road freight sector's transition to ZEVs.  Bernardo Galantini, Freight and Climate Officer at T&E says: "The Commission proposed a review of the W&D Directive a year and half ago but Member States have not yet reached a common position. This law is key to create the conditions for zero-emission trucks to compete with diesel rigs and accelerate the shift of the road freight sector to clean vehicles.

While the additional weight for ZEVs proposed by the Commission would speed up their adoption, they also have an impact on infrastructure. Our analysis shows how Member States could adjust the Commission's proposal to both promote ZEVs and safeguard Europe's roads and bridges. Reducing the proposed weight increase, e.g. the additional weight for 5-axle combinations from 4 to 3 tonnes and their driving axle from 12.50 to only 11.75 tonnes, is the right way to transport more cargo, lower costs and reduce road wear".

Bernardo Galantini adds: "With balanced weight allowances for ZEVs, we also urge Member States to remove the proposed limitation of heavier zero-emission trucks on parts of the TEN-T core network.

These restrictions are not necessary and even harmful to the transition of Europe's commercial vehicle industry".

References

1. ^ consultancy report (www.transportenvironment.org)