I think you need to separate the feelings that it apparently generates for you to see people running, from the actual reasons they are running. I guarantee they are not going out to exercise to show off for you or anyone else.

I'm sure they'd be happy to if they had the budget.

The other posts saying "normal city smarts" and "the whole city requires a reasonable degree of caution" are kinda sugarcoating things. Bladensburg Road by anybody's honest measure is gonna require a higher degree of caution than average. We don't know your comfort level. Are you a single woman living alone? Is it your first time living in a city this size? If so, it might not be the gentlest introduction. Some people will have good experiences, some won't. A bad experience could be life changing. If you are concerned, there are safer places to live. There are no prizes for charging ahead and there's no shame in looking out for yourself and choosing a less challenging neighborhood for your first place in DC.

Potter's Violin in Silver Spring, or Brobst in Alexandria. Both handle string instruments only, and will have upgrade paths for you, and apply rental credit towards a purchase.