From a recent Brooklynian.com exchange:
GUEST: How safe is it to walk from the Dekalb subway to the Clermont Avenue area near the BQE in the late PM and very early AM (1-3 AM) hours for women in their 20's? And are there cabs available outside the subway at those hours?
URBAN COWGIRL: I am a single girl in my middish-twenties and I live in just the area you're referencing. It is somewhat dangerous to walk home late in any neighborhood but, after living in other neighborhoods in Brooklyn and Queens, I've found this one to be the most disconcerting. Aside from taking a cab home from wherever it is I've been, I've found the least dangerous route home to be the F train to Jay street and then the B54 up Myrtle. The Jay Street area is well lit and usually somewhat crowded and the B54 runs often. Otherwise, if you DO decide to walk home from the train, choose one of the brighter streets (like Clinton Ave and unlike Waverly or Vanderbilt). Do not listen to your ipod or talk on the cell phone. As I say, walk "with purpose". It is very unlikely that you will find a cab, however the myrtle avenue car service is very quick and inexpensive.
I know I sound paranoid, but I had my blackberry stolen and was knocked around a bit at 10 pm one night after coming home from a business trip. I had simply taken it from my pocket to check the time. I love this neighborhood and I do believe that the good outweighs the bad. Just stay alert.
DRKMAN: Using the Jay Street stop on the F train and then catching the B54 is the best route to go. If you have to utilize the DeKalb Avenue stop you can usually catch a cab on either Flatbush or Fulton by waving one down any time of the night. Walking late at night is not overly dangerous but you will have to be alert and I would not walk the same route on a consistent basis.