Which is the correct place to install this sign?
💡 Hint
As a rule, caution signs are installed on the right side of the road BEFORE the hazard so drivers can prepare before reaching it (Enforcement Rule, Appendix 6). Judge each position by asking when and where the sign must be seen by drivers to be useful.
Answer: ①
Explanation
A picture of an arched entrance is a caution sign warning of a tunnel (Enforcement Rule, Appendix 6, No. 138). Where there is a tunnel, it is placed on the right side of the road 50-200 meters before the tunnel entrance. Brightness changes suddenly when entering a tunnel, so slow down in advance and turn on your headlights. Placing it after the exit, in the middle of the road, or inside the tunnel does not match the installation criteria.
Legal basis: 도로교통법 시행규칙 별표6 138 터널표지