The question

I recently took my kids to a baseball park near my house. My daughter asked if she could run down the sidewalk to the play area. I said yes. She started running but when she came to a part of the sidewalk that comes to a small hill she fell and broke her arm. I would normally not think anything of it but there is a speed bump in the road and the speed bump is yellow so driers see its there. The sidewalk comes up at a slight angle and without any warning signs a kid running down the sidewalk won't notice the change in pitch and trip and fall. I'm just wondering if there is a way to get a yellow strip and a warning placed there?