Road traffic noise analysis in urban roundabouts: a systematic review

Introduction Road traffic noise is a major source of urban noise pollution and represents a significant public health concern, particularly in areas where populations are exposed to elevated noise levels. In this context, analyzing sound pressure levels across different traffic systems, especially at urban intersections such as signalized intersections and roundabouts, is essential for assessing noise exposure and supporting mitigation strategies. Methods This study conducts a systematic literature review based on pre-established inclusion and exclusion criteria to synthesize findings on road traffic noise around urban roundabouts. The reviewed studies primarily rely on field measurements, with widespread use of noise prediction models (e.g., NMPB-Routes, RLS-90, CNOSSOS-EU) and computational simulations. Results Most studies are concentrated in Europe and Asia, using tools such as CadnaA and Predictor LimA for sound mapping. Noise monitoring is commonly conducted during three daily periods with a sound level meter positioned at 1.5 m in height. Findings indicate that roundabouts generally present lower noise levels than signalized intersections, due to smoother traffic flow and fewer stopping, acceleration, and deceleration events. However, the literature remains methodologically fragmented, with limited standardization of measurement and modeling procedures. Conclusions Although roundabouts are generally associated with lower traffic noise levels, the presence of traffic lights may reduce or even reverse these acoustic benefits by modifying vehicle dynamics. These dynamics highlight the need for further investigation into the interaction between traffic control devices and noise levels in urban contexts.