his paper aims to evaluate the likely effects of the adoption of Longer Heavier Vehicles (LHVs) from the perspective of logistics service providers (LSPs). The research consists of six case studies and a survey of companies which were involved LHV trials in Germany. Wider introduction of LHVs is being increasingly demanded so that road freight transport can better serve and support modern supply chains whilst achieving the desired eco-efficiency advancements. Available literature on LHVs puts a particular emphasis on five factors that need to be included in the assessment of their impact: energy efficiency, CO2 emissions, costs, safety and infrastructure. The research provides an original and innovative empirical study refining and validating the current conceptual framework for assessing LHVs demonstrating it is a valuable tool and providing evidence that the vast majority of companies participating in our study, regardless of their size, were interested in the adoption of LHVs. However, it should be noted that a key limitation of the research is that by focusing on a single country case, the nature and scale of the findings may not reflect practice in other countries and sectors. There is also a need to examine the long-term sustainability of the improvements made.