Making dogs poop at the curb solves many problems. It is convenient for a lot of dog owners who may not have their own yards or find it difficult to take their pets to the park each day. Choosing the curb over the sidewalk prevents possible nasty surprises for unsuspecting pedestrians who may otherwise step in dog poop. Where sidewalks are extensions of somebody’s property, streets belong to the city and are cleaned regularly. Hence, when dogs are curb trained, their droppings are cleaned by the street sweepers even if the owner forgets to clean up after. This way random heaps of poop are never allowed to form and the streets remain clean as do the pedestrians' footwear.