What is the purpose of hold-short signs and lines near runways?

• A. They designate where cross only with explicit clearance to protect active runways.
• B. They indicate where not to cross without explicit clearance to protect active runways.
• C. They are decorative markings with no safety function.
• D. They designate maintenance work zones.

Answer: (B)

Hold-short lines mark the boundary where a taxiing aircraft or vehicle must stop and not proceed onto a runway without explicit clearance. They exist to prevent runway incursions by ensuring you don’t enter an active runway unless ATC has told you to cross. When you approach the boundary, the solid-line side is what you must stop at unless you’ve been cleared to cross; only with a direct cross clearance may you continue onto or across the runway area. This safety boundary protects both incoming and departing traffic by keeping runway entrances and exits free of unexpected crossings. It’s a crucial, practical rule used every day to keep operations on and around the runways safe.