All railway companies whose tracks cross or intersect any street in the city shall maintain at the crossings at all times either automatic signals, which shall glow or reflect red whenever a train is approaching or is thereon, or shall maintain a watchman to signal the approach of trains at each crossing during each hour of the day and night. However, the installation of crossing gates to be operated as each train approaches shall be considered sufficient under this section.
('75 Code, § 44.22) Penalty, see § 77.99