I have the same problem. I can sleep easily during the day. But at night it can be super hard to fall asleep. Even the slightest unexpected sound will get me.

You could try a masking sound, white noise or ocean sounds should mask traffic quite well. Not very loud, just loud enough to even out the variation. Good luck! Loss of sleep is terrible. I wrote about it recently: https://jacquesmattheij.com/dealing-with-insomnia/