This is pretty cool. I have been on my bike for about 15 hours straight, but never for 24 hours.

As you mentioned, any city would be alright in the overnight hours, provided that you stay on the main streets. It's only outside big cities that you have to be worried, on account of a lack of streetlights.

During my ride from New York to Washington in the summer of last year, I was on U.S. 40 for more than 60 miles through Delaware and Maryland. And I was shocked to observe that there were several sections without streetlights. There's a place you don't want to be at night.

Maybe I shouldn't have been so shocked. When I was a kid, I lived near the eastern border of New York City; and there tended to be no streetlights on the streets over the border in Nassau County. I got caught out there once or twice. And, of course, in those days I didn't have any lights on my bike or on my (nonexistent) helmet. And, if I remember correctly, at that time after New York City's Grand Central Parkway crossed the border and became Long Island's Northern State Parkway, the lights disappeared.

But if you can stay in urban areas during the overnight hours, you will surely enjoy the benefit of civilisation's most basic good, namely nighttime lumination.