What does the following safety sign mean?
On an indication sign with a split arrow, the directions of the branches are the directions you are to travel (Annex 6 of the Enforcement Rule). It is easy to confuse whether the side branch next to the upward one points left or right, so read the sign as seen from the front, and remember that a blue indication sign never means prohibition.
Answer: ④
Explanation
This indication sign, with an upward arrow and an arrow branching to the left, instructs vehicles to go straight or turn left (Enforcement Rule Annex 6, No. 309). If the arrow branched to the right it would mean straight or right, and if it only split left and right it would mean left or right turn. An indication sign tells vehicles to proceed that way; it does not prohibit.
Legal basis: 도로교통법 시행규칙 별표6 309 직진 및 좌회전표지