Its my experience that larger cities usually have far less CB traffic than more rural areas. Of course every city is different but I've got a pretty good setup and at most I only catch chatter on a couple of channels.

Not used as much in the city and relatively short range (unless your running a foot warmer) but better range then frs. Then the added useablility on channel 19 once your in a vehicle and on the way, between that and the scanner I can hear where accidents are or where traffic is stopped.
Ham is down the road but for noe I can buy used cb's for under $50 and outfit the whole family where portable HAM gear is ~$200 each.
I have some of those frs/gmrs radios but those the signal won't even make it out of the neighborhood.

My BOB is intended for several purposes:

* As the minimum equipment needed for an immediate evacuation emergency. If we need to get away from where we are, I should be able to sustain my family for three days, as long as I can find water and (hopefully) food.

* As the core of the more extensive emergency kit I've built; if I have my BOB (or my wife's BOB) plus the two bins, the water, we should be in good shape for at least two weeks, bugging in or bugging out.

* To sustain me if my car is stuck in a snow drift for a few days.

* As a get home bag if I have to hoof it home from anywhere within three days' walk.

* To carry gear that I use in non-emergencies. For example, I use the first aid kit seemingly constantly, I fixed a kid's bike with tools I had in my BOB during a camping trip, and most recently I produced a pair of fresh AAA batteries for the instructor of the class I'm in so that he could use his presentation remote. This use calls for diligent restocking as items are consumed.

Much of the gear is biased towards rural/wilderness use, but there are some items I've found quite handy for urban and suburban needs.

The consequence of this combination of uses is that it's heavy. I wouldn't want to walk home more than, say, ten miles carrying it. Since it lives in my car, I'd rather have too much than too little. If I do find myself needing to walk out of something, my plan is to cache stuff that isn't as likely to be needed, based on the situation.