Noise Pollution in Urban Transport: A Systematic Review of Health Impacts from Buses, Trains, and Motorcycles

Transportation noise pollution is a critical environmental and public health concern, particularly in urban areas where increasing traffic density contributes to elevated noise levels. Prolonged exposure to excessive transport noise has been associated with adverse health effects, including hearing impairment, sleep disturbances, increased stress levels, and an elevated risk of cardiovascular diseases. This systematic review examines noise pollution across various transport modes—including buses, cars, trucks, motorcycles, subways, and aircraft—and compares recorded noise levels to the World Health Organization (WHO) standard limits. The findings indicate that several transport modes exceed recommended thresholds, with motorcycles (88.9 dBA), heavy trucks (87.5 dBA), and auto-rickshaws (85.5 dBA) surpassing their respective limits of 85 dBA, 85 dBA, and 82 dBA. Among public transport options, buses exhibit an average noise level of 81.91 dBA, exceeding the standard of 80 dBA, while subways (79.8 dBA) and streetcars (71.5 dBA) remain within acceptable limits. The highest recorded noise level was for commercial passenger aircraft at 135.0 dBA, whereas the lowest was for bicycles at 69.65 dBA, remaining below the 70 dBA threshold. The most frequently reported sources of excessive noise in urban transport, including engine vibrations, exhaust systems, tire-road interactions, and sudden vehicle movements. Furthermore, this review evaluates various mitigation strategies, emphasizing the role of advancements in vehicle technology, infrastructure modifications, traffic management, and policy enforcement in reducing transportation noise. The adoption of electric and hybrid vehicles, noise-absorbing road surfaces, urban green spaces, and stricter noise regulations are identified as effective strategies; however, persistent high noise exposure suggests that current measures require more robust implementation and enforcement. By providing a comprehensive assessment of urban transportation noise levels and their health implications, this study highlights the necessity for enhanced noise regulation and mitigation efforts. Its findings offer valuable insights for policymakers, urban planners, and public health officials in developing evidence-based strategies to minimize noise pollution and its associated health risks. Given the increasing reliance on public and private transportation, addressing transport noise pollution is imperative to fostering healthier and more sustainable urban environments.