Check out the location of these condos in downtown Toronto built alongside the Gardiner Expressway, a very busy 90km/h (~55mph) highway: https://maps.app.goo.gl/TGLCBJGbrSEkAm7W6
Years ago I lived near a busy four-lane road with what seemed like a reasonable 60km/h speed limit. However, when it rained, the noise from the car tires on the wet road made it difficult to hear music from my radio. It was very unpleasant to leave the balcony doors open, as the constant din starts to work its way into your brain and make it very difficult to focus.
The satellite view shows many units in multiple buildings directly next to this highway with no noise protection: https://maps.app.goo.gl/JA4jMPSSYsDBq5my5
Years ago I lived near a busy four-lane road with what seemed like a reasonable 60km/h speed limit. However, when it rained, the noise from the car tires on the wet road made it difficult to hear music from my radio. It was very unpleasant to leave the balcony doors open, as the constant din starts to work its way into your brain and make it very difficult to focus.