Require all dogs to be kept on leads in public places

I have an assistance dog who assists with my mobility. Other dogs off lead are a regular problem bounding towards him and ultimately knocking me off balance. I have observed others such as the elderly, children and cyclists be subjected to off lead dog problems also. It would help with dog fouling as those whose dogs are off lead foul freely and it's not picked up as the owner doesn't see it. Multiple dogs off lead is an even bigger problem and also dangerous spoiling everyone's enjoyment.