Evaluation of Road Traffic Noise Pollution Using the Inverse Distance Weighted (IDW) Interpolation Method in the Municipality of Ain Benian, Algiers, Algeria

Urban road traffic noise has become a growing public health concern in North African cities, yet systematic acoustic assessments remain rare in this region. This study maps noise exposure in Ain Benian municipality (Algiers, Algeria) through georeferenced field measurements at 63 sampling points distributed across three urban zones, conducted during morning, midday, and evening periods. A resident perception survey (n = 170) complemented the acoustic dataset. Continuous noise maps were produced by Inverse Distance Weighting (IDW) spatial interpolation in ArcGIS and cross-validated using leave-one-out cross-validation (LOOCV; RMSE ≈ 5.1 dB(A)). Recorded levels peaked at 77–78 dB(A) during commuting hours and fell to roughly 65 dB(A) at midday — a difference of more than 12 dB pointing squarely to traffic as the controlling factor. Eighty-nine percent of stations exceeded the Algerian daytime threshold of 70 dB(A), and spatial analysis shows that close to half the municipality experiences levels above 75 dB(A), predominantly along the RN11 and CW111 corridors. An indicative day-evening-night level (Lden) was estimated for contextual purposes only; given the absence of nocturnal measurements, it carries appreciable uncertainty and is not intended for regulatory use. The results underline the severity of the noise situation in Ain Benian and the urgency of targeted intervention in traffic management and urban planning.