Tree down blocking Sanctuary Blvd

Hello,
We live in a Cul de Sac ( Homeward Lane, Natick) with lots of little children playing outside in the neighborhood. We are noticing that a lot of cars are not adhering to the 20 mph speed limit posted and we are very worried about this. Also, there is an intersection which has a giant pine tree blinding two sides of the intersection. We collectively think having a couple of speed bumps near the intersection of Homeward Ln and Westview road would help reduce the speeding problem. Please let us know what should be the steps to request this.