Would you mind linking to the list you’re referring to? My off-the-cuff thought was, “join Transportation Alternatives and push for more bike lanes, public transit, etc.”, as I see automobiles as one of the most significant dangers to both urban areas and even the planet. But when I google "ten most dangerous cities," they seem to list places whose danger is more poverty-driven.
I think you might be in a minority of people that hear "dangerous" and then think about transportation first. My guess would be most people think of danger as violent crimes. At the same time, people are aware of other types of accidental deaths, but may view those differently because they feel they have more control over them.
Bikes might not be a great solution in these areas -- they're easy to steal and somewhat unreliable due to weather and other factors. And, if somebody already feels that they're taking a risk hiring a poor person... is it going to help if they're showing up sweaty? Perceptions matter on both sides of the equation -- I won't apply for a job if I don't think that I'd last a week.
Rather than focus on the impact of cars, which is a bit of a "boil the ocean" solution, it would be directly impactful to fund a local restauranteur. It makes local jobs, and makes the neighborhood more livable and walkable.
If I had a billion dollars, I'd do an incubator for small, local businesses focused on sustainability, not disruption.