lil brown bat

I'm also female. What Pezzle says rings true although I haven't had the experience: plans tend to go out the window when things go wrong. You're asking what I do, which, frankly, seems like the wrong way to go about it. What I would do is not what you should do.

What should you do? Here's what I would suggest.

1. Make a realistic assessment of the threat. When people describe an area as "sketchy", they may be onto something, or they may be reacting based on a stereotype. It's a good idea to talk to the local police or read the police blotter to find out about the actual incidence of crime in the area in question. What's the frequency and nature of the crimes? Who is targeted and why? Yes, it happens, but middle-class women aren't the most common targets of violent stranger-on-stranger crimes.
2. Consider the tools and resources at your disposal. People most often think first of weapons, for exactly the wrong reason: because they think having a weapon is a substitute for self-defense skills. No weapon works if you don't have the skills to use it, and developing and maintaining skill takes time and practice. Are you willing to do that? If not, a weapon is probably not the route for you. Martial arts, even more so -- I train in martial arts and love it, but if someone has a self-defense problem show up on their doorstep today, I wouldn't recommend going out and studying a martial art, because the skill curve is such that it won't help you soon enough. The resources that people usually overlook are knowledge of the actual situation, common sense, and the ability to identify and avoid dangerous situations.
3. Decide whether to continue riding that route, and under what circumstances. You might decide to only ride at certain times of day, or only if you can do so in company with others; you might decide to continue to monitor crime reports so that you'll be aware if the situation changes.

One, two, three. As my old sensei said, "It's simple...it's NOT easy." But it's just what you've got to do.