August sees most expressway casualties from daytime drowsy driving, wet-road crashes

Drivers heading onto expressways this August vacation season are urged to take extra care against drowsy driving during daytime hours and wet-road accidents caused by localized heavy rain.

An analysis by the Korea Expressway Corporation of expressway traffic accidents in August over the past three years (2023–2025) found that daytime casualties — those occurring between 9 a.m. and 6 p.m. — totaled 19, the highest of any month of the year. Trips of 100 kilometers or more accounted for the largest share of those fatalities and injuries.

The corporation attributed the trend to fatigue built up during long drives in extreme heat, compounded by extended use of air conditioning in recirculation mode, which raises carbon dioxide levels inside the vehicle and induces drowsiness.

August also recorded the year's highest risk of wet-road accidents. Over the same three-year period, wet-road crashes in August claimed 10 lives — the highest monthly toll. According to the Korea Road Traffic Authority, the fatality rate for expressway wet-road accidents over the past five years stood at 4.7 deaths per 100 crashes, roughly 1.4 times the rate on clear days (3.4), underscoring the risk of serious collisions.

To prevent wet-road accidents, drivers should reduce speed by at least 20 percent in normal rain and by more than 50 percent in heavy downpours, while maintaining a following distance at least twice the usual gap. On flooded sections, drivers should pass through slowly without stopping.

"August is a dangerous period when drowsy driving caused by extreme heat and wet-road accidents from sudden localized downpours occur frequently," a Korea Expressway Corporation official said. "On long drives, open the windows regularly to ventilate the cabin, and if you feel drowsy, pull over immediately at a rest stop or drowsy-driver rest area."

Meanwhile, the Korea Expressway Corporation is running a public safety campaign titled "Finding Expressway Hazards on Your Vacation Route" through Aug. 20. The initiative invites the public to report hazards spotted while driving on expressways or using rest facilities during the vacation season — submitting photos so the corporation can inspect the scene immediately and take corrective action.