Noise exposure of cyclists in Ho Chi Minh City: A spatio-temporal analysis using non-linear models

Cyclists′ Exposure to Road Traffic Noise: A Comparison of Three North American and European Cities

“…For example, a recent study based on data collection by bicycle through the streets of Ho Chi Minh City (1035 km) has shown that the levels of cyclists exposure were particularly high (mean = 78.8 dB(A)). This study also demonstrated that these noise levels vary significantly according to the type of road taken by cyclists; compared with a residential street, spending one minute on a trunk, primary, secondary, or tertiary road increases mean noise exposure (5.1, 3.4, 3.1, and 2.2 dB(A), respectively) [32].…”

“…The model proposed here is largely based on a recent study [32]. First, we used GAMMAR models (generalized additive mixed model with an autoregressive term) with a scaled t-distribution for the dependent variable [43].…”

“…As done by Gelb and Apparicio [32], to take the temporal and spatial variabilities of traffic into account, the time of day (number of minutes passed since 07:00) and the geographic coordinates were introduced as non-linear terms (i.e., splines). Therefore, we expected to observe peaks of noise during the morning and evening rush hour periods, and in the central districts of each city.…”

“…The obtained Bayes R-squared are relatively similar among the three models: 0.491, 0.505, and 0.439 for Copenhagen, Montreal, and Paris, respectively, when keeping only the fixed effects, and 0.507, 0.516, and 0.441, respectively, with the random effects. To measure the temporal dependence of the residuals' models, we calculated the autocorrelation function (ACF) index [32]. The obtained values suggest there is no temporal dependency in the residuals for the Copenhagen model (ACF at lag 2 = −0.024, lag 3 = 0.023, lag 4 = 0.063), Montreal model (ACF at lag 2 = −0.031, lag 3 = 0.006, lag 4 = 0.045), and Paris model (ACF at lag 2 = −0.016, lag 3 = 0.016, lag 4 = 0.002).…”

“…8, 66.8, and 74.0 dB(A), respectively). Even rarer are the urban studies that examine the variations of cyclists exposure to road traffic noise according to characteristics of the route taken by the cyclists [26,28,32]. The present work falls within this stream of studies.…”