Final answer:
According to OSHA standards, walkways must have handrails when they are 30 inches or more above the lower level to prevent falls and ensure safety.
Step-by-step explanation:
The question relates to construction safety regulations regarding walkways and when they require handrails. According to the Occupational Safety and Health Administration (OSHA) standards, specifically regulation 29 CFR 1910.29, walkways must have handrails when they are 30 inches (76 cm) or more above the lower level. This ensures the safety of individuals using the walkway by preventing falls. These regulations apply to various work environments such as construction sites, industrial facilities, and public access areas. It is important for structures to adhere to these safety guidelines to protect users and comply with legal safety requirements.