[niwell]

Historically it seems that in many larger cities people just shut themselves inside once it got dark out. Being outside at night could be a dangerous proposition. If we want to talk about a natural state of affairs I don't think large cities would really exist - we'd all be living in rural areas or at most small towns. Street lighting arose tackle a real issue.

There are probably lower density areas that could do well with some of the street lights (maybe not all) turned off after a certain time. Traffic is also a consideration, of course.