Question

which best describes a development that improved railroad safety?
railroads adopted standard time to coordinate schedules.
railroads offered fold - down beds so that people could sleep more comfortably.
companies standardized track technology so that they could use each other’s tracks.
companies replaced hand - operated brakes with air brakes on trains.

Explanation:

To determine which development improved railroad safety, we analyze each option:

• Adopting standard time (first option) helps with scheduling but doesn't directly enhance safety.
• Offering fold - down beds (second option) improves passenger comfort, not safety.
• Standardizing track technology (third option) is about interoperability of tracks, not safety.
• Replacing hand - operated brakes with air brakes (fourth option) directly impacts safety. Hand - operated brakes were less reliable, while air brakes provide more consistent and effective braking, reducing the risk of accidents.

Answer:

D. Companies replaced hand - operated brakes with air brakes on trains