<i>At least in Europe it is considered almost always.</i><p>I should have appended &quot;in the USA&quot; to that sentence. Europe is far, far ahead of us in terms of addressing noise in general and transportation noise in particular.<p>For example, many Americans may have noticed that kitchen&#x2F;home appliances (dishwashers, washing machines, etc) have gotten significantly quieter over the last decade or so. The reason for that is that an EU directive set maximum noise levels for common appliances. Because many manufacturers sell the same units to the US and to Europe, they designed all of their   products to meet the noise spec and we Americans got the benefit.<p>In terms of transportation noise, I am continually blown away by the public and private sector support consultants in western Europe get in support of noise analysis and noise mapping. I&#x27;ve seen projects in Europe spend more money address flow noise from a high-speed rail door handle than we get addressing noise over an entire rail corridor.