I'm all for neighborhood patrols/neighborhood watch, but as a commuter downtown every weekday, I'd say a good place to start would be to stop your car at red lights and stop signs and also to use your turn signals to signal a turn. If you are walking, try to cross at the light, or if you can't, hustle your body across the street as to not cause cars to either stop dead in the middle of a block or dart about wildly trying to avoid you.

The old adage about sweeping your own doorstep every day might be a good starting point too.