I don't even remember the 2004 cicadas. I was working in silver spring then and living in frederick county and, outside of the news, didn't know there was an event occuring. In rockville there were a lot more in one of the broods in the 90s (although I don't remember the year, seems like it would've been late 90s as I brought one home to show my little kids since we didn't have any in college park). I didn't have any issues cycling around rockville back then and there were lots of cicadas (you had people using umbrellas to go in to the building from the parking lot
). I'm betting the amount of construction in rockville since then has eliminated a lot from that brood.