Children are absolutely large enough to be noticed. The issue is that car drivers think it's okay to ignore them. They're choosing only to look at cars because

Children are absolutely large enough to be noticed. The issue is that car drivers think it's okay to ignore them. They're choosing only to look at cars because we train people from a young age to think of the black stuff as a space where only cars go. And because we make it illegal to drive safely. If you knew you were going to get treated the same for threatening a small child with a car as with any other lethal weapon, you'd drive much more safely.