Pre-industrial city streets emptied at dark and felt dangerous.

Evidence

Night begins to fall and more and more people disappear from the streets. No lamps light the impending darkness. The sounds diminish with the light and you are suddenly afraid. For a while, nothing stirs. You can hear the occasional step of the night-watch, patrolling the deserted streets, the occasional cry of the watchman that all is well. — Lyn H. Lofland, World of Strangers_ Order and Action in…, 169