It shall be the duty of any person owning, controlling or using any track or part of a track which shall be laid upon, along or across any street, alley or sidewalk within the city to pave between and on each side of the rails of such track where it crosses any such street, alley or sidewalk with some durable hard surface material at the same elevation as the rails of the track; provided, that all of such crossings referred to in this section shall be maintained and kept in good repair at all times. (Prior code § 25-5)