Sorry to burst your bubble.

"basic traffic noise from highways won’t get perceptibly quieter due to electric cars. Urban road traffic noise below 40 kph likely will, as engine noise starts to dominate at lower speeds. And we can all look forward to fewer and fewer noisy motorcycles and trucks, and no economy cars with broken mufflers."

https://cleantechnica.com/2016/06/05/will-electric-cars-make-traffic-quieter-yes-no/