All tracks constructed on the streets of the city, over which rights-of-way have been granted, or which may hereafter be granted, shall be put in good order. The space from the centerline of the street, which is also to be considered as the centerline of the track, including all switches and turnouts, shall be filled their entire length with the same material of which the street is constructed, or its equivalent, or in the case of unimproved streets with plank or some good ballasting material.
(1964 Code, § 31-21)