The deliverable ‘Recommendations for Quieter and Cleaner L-Vehicles’ summarised evidence-based guidance on how to reduce air pollutant and noise emissions from L-category vehicles, including mopeds, motorcycles, tricycles and quadricycles, across Europe. A concise summary of this document is also available as our LENS final brochure.
Produced as the final deliverable of LENS, the document brings together findings from extensive testing, real-world measurements, technical analysis, and supports policymakers, regulators, enforcement authorities, cities, manufacturers and riders in improving environmental performance, strengthening regulation and enabling more effective mitigation measures for quieter and cleaner mobility.
A key conclusion of the report is that current type-approval procedures do not adequately reflect real-world vehicle use. Laboratory test cycles often fail to capture operating conditions that strongly influence emissions and noise, such as cold starts, rapid accelerations, high engine loads and variable urban driving patterns. Measurements from 150 vehicles showed that pollutant emissions, particularly carbon monoxide, frequently exceed type-approval values during everyday use. Similarly, noise levels recorded in real traffic conditions were often higher than regulatory limits, especially during transient events that are not sufficiently represented in existing tests. These findings demonstrate the need for regulatory approaches that better mirror real driving behaviour.
The authors recommend improvements to type-approval regulations to ensure more realistic and robust testing. Proposed measures include expanding test cycles to cover a wider range of driving conditions, introducing limits for currently unregulated pollutants such as ultra-fine particles, and refining how different L-vehicle subcategories are tested. The document highlights the growing maturity of portable and smart emission measurement systems as tools that could be more widely used for on-road testing, enforcement and market surveillance.
Vehicle tampering is identified as a major contributor to excessive emissions and noise. Inspections carried out during the project revealed widespread modifications to exhaust systems, engine control units and air intake components, often driven by performance or sound preferences. Such practices significantly undermine environmental objectives and regulatory efforts. To address this, the report calls for stronger anti-tampering measures, including targeted periodic inspections, improved roadside checks and more effective market surveillance to restrict non-compliant aftermarket parts.
Beyond regulation and enforcement, the report emphasises the role of local policies and user behaviour. Measures such as low-emission zones with targeted detection of high-emission L-vehicles, access restrictions in sensitive urban areas and public awareness campaigns are recommended. Digital tools that provide riders with feedback on their emissions and noise impacts are also highlighted as promising ways to encourage cleaner and quieter driving behaviour.
Finally, the report stresses the importance of accelerating fleet renewal, particularly the transition towards electric L-vehicles, while ensuring that emission control technologies perform effectively under real-world conditions. Cost–benefit analyses indicate that a combination of regulatory improvements, enforcement, behavioural measures and technological change can significantly reduce the environmental footprint of L-category vehicles over the long term, while maintaining their role in sustainable urban mobility.