Tip regarding radio: 2182kHz SSB near the coast. That frequency is monitored by authorities globally. It's the MF equivalent of maritime VHF ch16.

Technically, the same goes for 2187.5kHz, but that's for digital transmission only, and unless you have the required hardware to encode/decode it, you won't be able to make sense of it.

Source: I have a GOC

There is also amateur radio (aka ham radio), which can legally and practically operate at higher output powers if necessary, and on far more frequencies than CB. Although doomsday people often say to just buy a ham radio and use it without a license, I don't advise that, simply because having the radio is only half the challenge.

The other half is the ability to competently operate the radio to effectively communicate and organize aid. And this only comes with practice by talking to others, in the form of regular participation in radio nets and/or emcomm activities. Emergency radio isn't even limited to voice transmissions, with digital modes and even fax modes being an option that can transmit quicker and farther. Having a legit call sign will make it easier for rescuers to identify your transmissions, as well as figuring out if you've been located.

While some people will make ham radio a lifelong hobby, others obtain their license simply for small-talk, or for a SHTF scenario, or as longer-distance walkie-talkies when camping in heavily wooded forests. The possibilities are endless, but it all starts with a first radio and some basic training on radio handling.

Ham radio clubs across the USA and the world are generally very welcoming of new folks, so it's worth looking up your nearby club or dropping in on an in-person club meeting.

The CB radio thing is going to be very location specific, I work in 911 dispatch, I think the state police around me theoretically monitor channel 9 on the highways, but in practice I wouldn't have a lot of confidence in that, they barely look at info we send them over the computer, CB also has a somewhat limited range, so you're counting on them having an officer somewhat nearby or you being close to their station.

As for local police, around me I suspect a few of them probably still have a CB antenna on the roof of their station and maybe even an old radio stashed somewhere in a closet but not hooked up and not being monitored, and the officers definitely don't have them in their vehicles.

I'm in a pretty dense suburban area outside of a major city, they might still get some use in more rural areas where cell signals aren't as reliable, though you're probably going to run into the same issues with range limitations, in normal ideal conditions, you might get a range of about 20 miles or so, depending on atmospheric conditions, geography, etc. you might get only a fraction of that.

EDIT: FWIW, I keep a CB in my car, decent amount of chatter still happens on 19 around me, and a few other channels, and somehow channel 9 seems to have become essentially the Spanish language channel.

How long would I have to stay indoors? A week? A month?