the WMATA isn't encrypted either, before the ProVoice upgrade came out that was my first listening experience with transit. There are also quite a few even federal agencies that aren't encrypted, and the colleges are usually DMR trunked, some encrypted, some not. I think I might still have a favorites list from DC. Add the surrounding P25 systems into it (Arlington County, etc), and while you'll definitely notice a bit of a drop compared to MA, I was never bored.
My apologies, I should've been clearer. What I meant was, before the ProVoice upgrade came out to listen to the MBTA, my first experience listening to rapid transit was the WMATA when I was in DC. They operate mostly on P25, but some bus talkgroups are analog. Also a blast to listen to is the US Park Police on VHF analog conventional, they handle quite a bit in the city and the roads surrounding it. Think what the MDC Police was but for the DC area.
I live in the District. My radio is programmed for:
DC's trunked system: FD and the citywides are not encrypted.
WMATA: not encrypted, and actually gets some action. Some of the metro stations aren't in great areas, and things can pop off pretty good from time to time.
Montgomery County: Majority of the system isn't encrypted.
Prince George's County: Majority of the system isn't encrypted.
Pretty much everything on the Virginia side of the river isn't encrypted. So Arlington, Alexandria, etc.
Park Police isn't encrypted, and uses analog conventional.
You won't hear MPD unless they're on the citywides. You won't hear Secret Service, or Capitol Police.
I should add: Prince George's County is the most action packed. That PD runs their butts off, and gets quite a few shootings and stabbings, etc. Pursuits....officer involved shootings...that's a great system to monitor! Lots going on over there!