I wouldn’t have a problem walking anywhere in NW DC at 8pm (dark or not). Running should be safer. The only places I’d avoid are North Capitol St itself (unpleasant on multiple levels) and Rock Creek Park after dark (Chandra Levy was killed running there).

I can’t think of any place in NW DC where if I lived there I’d feel uncomfortable walking in my neighborhood at 7-8pm. I dunno, maybe avoid Sursum Corda too.