Acoustic Indicators for Motor Race Noise: Definition, Validation, and Tests in Simulated and Real Races

Although the road transport sector, together with railways, airports, and industries represent the major contributors to noise pollution in Europe, also other minor activities, scarcely explored in the literature, can have a non-negligible role on a local scale. This is the case of motorsport races. During these types of events, vehicles produce notable noise emissions while are on track during tests, qualifying, and race sessions. As a consequence, they may, directly or indirectly, affect the well-being of inhabitants in the surrounding area of the circuit, and expose the public, workers, and all the other possible Noise Sensitive Receivers (NSRs) to high noise levels. Therefore, a thorough analysis of the noise levels produced during motorsport events at sensible receivers is strongly needed, to better assess NSRs’ exposure and gather information on the possible measures to reduce noise to acceptable levels. This works aims to address this topic, by proposing the definition of two noise indicators: the Lap Equivalent Level (LEL) and the Race Equivalent Level (REL). LEL defines the equivalent noise level at a certain receiver due to a single-vehicle track lap, and REL the equivalent noise level produced during a race. Noise data were collected on different points along a racing circuit during a single-vehicle track test and different car races, to apply in practice the defined indicators. Measurements show that the REL tends to stabilize its values during a race, suggesting that its modeling can be achieved based on the average LEL and the number of vehicles participating in a race. Instead, the duration of the race does not play a key role in the estimation of REL values but, rather, gives information on the NSRs’ exposure time to race noise levels. Estimations of RELs were carried out for real and simulated races. A comparison with available measured values shows good performance of the indicators suggesting that the proposed approach could be appropriate.