Any person authorized to do any work described in this chapter must, at the time of the excavation and until the place is restored to its original condition, construct and maintain an appropriate bridge across said work for the passage of pedestrians at all times. At night, such persons shall place and maintain a red light on each side of said bridge to warn the public, and said bridge shall have banisters or guardrails, if any ditch is left open on either side. Torches may be used in place of the red lights herein required. (1988 Code § 14-206)