I was thinking as I was looking at some pictures of others bug out bags. All of them were well equipped but looked more like something a person would wear to storm a beach during war. Nothing wrong with that but if an urban survivalist got on a bus packing that stuff the police will likely be waiting at the next stop to take him off.

With a major urban setting as a likely target of terrorists it makes sense to be ready. A briefcase would make a good get back home kit and would draw no attention in a city. Packed and locked it could even be left at work without notice.

Another answer would be a student backpack. Sew on a peace sign or save the whales patch on the back but fill it with serious tools of survival that will save your hide. You will look like a brain washed liberal tree hugger. Who cares what they don't know.