I had already decided to change my homeward route to something both safer and with luck having fewer steep hills (going up that is). One of the advantages and disadvantages of riding a bicycle is that you get to learn the topology in a very intimate way - every downhill beckons like an old friend into a warm pub, while the uphills, though good for anaerobic stimulation, cause a sinking filling in that part of the brain set aside by nature for mapping bicycle excursions (unless you are a competition cyclist).
You also get to see the social ups and downs of a place, and something had told me that returning at 10pm via the road I had come along at 7pm would be a bad idea. It wasn't a good idea at 7pm, but I had no idea until I was actually going along it that I had picked a worrying street, and once on it, I didn't want to risk getting lost or potentially going into an even more alarming district.
So it just as well that I had worked out a quite different return route, because as I was leaving my meeting-which-turned-out-to-be-a-big party (put on by SXSW in San Francisco) a distraught young fellow asked me which way I was cycling home. He had a skateboard under his arm, so I spent a moment trying to do mental somersaults - did he want me to give him a tow home? Perhaps he needed directions, in which case I am about the last person on the planet to ask, unless I have a GPS device in my hand.
I told him I had arrived by the street behind us but was contemplating a different route. Then he blurted out that someone had just pulled a gun on him on that street, and he had fallen off his skateboard, smashing half his watch and catching some grazes. Mainly however he was scared - which seemed like a very sensible reaction.
I took his advice and mine, and went home in a completely different direction - which happily also avoided most of the hills. I was very wary all the way - always a good idea on a bicycle, though one is not normally, I hope, watching out for people with guns. But maybe city cyclists need a couple of extra markings on the cycling maps, beyond which streets have less cars on them: how about something to show the gradients of hills in flashing neon (there are a couple of maps with gradients marked, but the markings are too tame) and something to show which areas are not so safe at night. Both of these could be interactive, as long as the printout came out well.
Utilitarian cycling will just have to become much more popular for many reasons and it will be much easier to promote it if people, especially women, feel fairly safe whilst doing it, which in turn will make it easier to enjoy one of the great benefits of travelling without being sheathed in a metal box, namely that you can start to get to know your locale in a much more intimate and detailed way.