1. The defendant's appeal is dismissed.

2. The appeal costs are all the Defendant, including the costs incurred by the supplementary participation.

1. Basic facts

A. The Plaintiff is an insurer who has concluded an automobile insurance contract with the Plaintiff’s Intervenor regarding the Plaintiff’s Intervenor and BSP vehicle (hereinafter “Plaintiff’s vehicle”). The Defendant is an insurer who has concluded an automobile insurance contract with respect to Ci30 vehicles (hereinafter “Defendant’s vehicle”).

B. On June 16, 2017, around 08:50, there was an accident that conflicts with the Plaintiff’s vehicle following the two-lanes while the Defendant’s vehicle driving in the two-lanes with the two-lanes, as the vehicle in the front side was at string the two-lanes.

C. On June 30, 2017, the Plaintiff paid KRW 880,000 to D with the repair cost of the Plaintiff’s vehicle.

【Ground of recognition】 The fact that there is no dispute, Gap 1 through 9, Eul 1, and the purport of the whole pleading

2. Summary of the parties' arguments

A. In light of the fact that the Plaintiff and the Plaintiff’s Intervenor used cargo vehicles on the rear side of the Defendant’s vehicle, which could not immediately become aware of the change of the Defendant’s vehicle, and that the Defendant’s vehicle did not operate the direction, etc. while changing the lane, it is reasonable to deem that the said accident was caused by the negligence of the Defendant’s vehicle entirely.

B. The Plaintiff’s vehicle was fully aware of the change of the Defendant’s vehicle prior to the occurrence of the accident, and it is reasonable to view that the error ratio of the Plaintiff’s vehicle in the instant accident is more than 30%.

3. The following circumstances acknowledged by the evidence and the purport of the entire pleadings, namely, ① the first lane in which the Defendant’s vehicle was in progress at the time of the said accident, was stopped by a large number of vehicles at a fixed body, while the Plaintiff’s vehicle was in progress, the passage of the vehicle was smooth. The Defendant’s vehicle stops after the frontline of the vehicle, immediately attempted to change its course into the second lane, and immediately thereafter, the said accident occurred. ② The upper part front of the right side of the Defendant’s vehicle at the time of the said accident and the front part of the left side of the Plaintiff’s vehicle.