Lights at night is not nessesary. You can wear a torch and so you can see. travel by night isn't advisable. Life IS feudal!
Actually some big towns or cities (like mine) want to have lamp posts or at least some forms of light so the guards, the citizens, and workers will be able to run around with their tools or weapons (bows and quivers don't fit if you have a torch on your back) and be able to take advantage of the raiders who attempt to raid our settlement, and can never use both half handed swords and shields or bows and arrows because they use torches most of the time. So I think that a new night lighting system is probably wanted for big cities and settlements .