Mapping road traffic noise descriptors in a sub-Saharan city: An extensivae mobile data collection in Abidjan (Ivory Coast)

Road traffic noise is an issue which can impact the well-being and health of urban populations. Mapping this pollution at a fine scale is essential for urban planning and public health. Most of urban road noise mapping studies have been carried out in northern cities. However, the issue of road noise is particularly compelling in cities of the Global South. Conducted in Abidjan (Ivory Coast), this study has three goals: 1) to collect data on several road traffic noise descriptors ( L Aeq,30s , L Amin , L Amax , L A10 , L A50 , and L A90 ); 2) to identify the road environmental characteristics significantly affecting noise levels; and 3) to produce noise exposure maps displaying these various noise descriptors for the entire city. An analysis conducted using Bayesian generalized additive models with an autoregressive term (GAMAR) reveals that the most relevant noise predictors are the type of route taken; the presence of traffic signals; the distance to the nearest major road; and the geographical location (the spline with geographic coordinates). The road noise potential exposure maps obtained with these models show extremely significant differences in noise between residential streets and major roads, but also between some regions of the city, despite all else being equal.