I am also a light sleeper. I lived in the centre of the city for almost three years. I used to get woken up at all hours. I started off with earplugs, but those hurt my ears. Eventually I started shutting my windows and curtains and putting a powerful fan on and it really works well.

Edit: a bonus one gets with the fan is that it also cools you off during summer when a shut window might have caused problems otherwise. (Aircon is uncommon here.)