One of the undesirable outcomes of the rapid travel of a large number of vehicles on highways is the high level of noise pollution. Tehran is the most noise-polluted city in Iran, where the contribution of motorcycles to noise pollution is significant. In this paper, the equivalent sound pressure levels (L_Aeq,1h) were measured alongside seven highways in Tehran and were compared with the environmental guidelines. The traffic-noise-prediction model for highways proposed by the government (IR-TNM) was also evaluated based on the collected data from field measurements. The findings reveal that traffic noise levels at measured points exceeded the maximum noise level allowed by Iran's Department of the Environment. Also, there was a significant difference between the results of the prediction model and measured values at the measured points. As highway access for motorcycles in Tehran is not prohibited and their impact on highway noise is not considered in the IR-TNM prediction model, a modification of the model, considering the motorcycle traffic and re-estimating the coefficients, was performed using the Gauss–Newton method, which led to a better fit to the observed data both for the calibration and validation data sets.

中文翻译：

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摩托车交通量大的高速公路的改进噪声预测模型

大量车辆在高速公路上快速行驶的不良后果之一是高水平的噪音污染。德黑兰是伊朗噪音污染最严重的城市，摩托车对噪音污染的贡献很大。在本文中，等效声压级 ( L _Aeq,1h) 沿着德黑兰的 7 条高速公路进行测量，并与环境指南进行了比较。政府提出的高速公路交通噪声预测模型 (IR-TNM) 也根据现场测量收集的数据进行了评估。调查结果显示，测量点的交通噪音水平超过了伊朗环境部允许的最大噪音水平。此外，预测模型的结果与测量点的测量值之间存在显着差异。由于德黑兰不禁止摩托车进入高速公路，并且在 IR-TNM 预测模型中未考虑它们对高速公路噪声的影响，因此使用 Gauss 对模型进行了修改，考虑了摩托车交通并重新估计了系数——牛顿法，