Driving in Bad Weather

📉Legal speed reductions

In Korea, the Enforcement Rule of the Road Traffic Act requires driving slower than the posted maximum in bad weather. Where variable speed-limit signs show a speed, follow that speed.

• Reduce by 20% of the maximum speed: when rain has wet the road surface, or when less than 20 mm of snow has settled.
• Reduce by 50% of the maximum speed: when visibility is 100 m or less due to heavy rain, heavy snow or fog; when the road is icy; or when 20 mm or more of snow has settled.
• Example: on an expressway with a 100 km/h limit, the maximum on a wet road is 80 km/h; on ice or with visibility under 100 m, it is 50 km/h.

☔Wet roads and hydroplaning

On wet roads, a film of water can form between tire and road so the tire rides on the water — hydroplaning. It is more likely at higher speeds, with worn tires and with low tire pressure. Steering and brakes barely respond.

If you feel it happening, avoid sudden braking or steering, ease off the accelerator to slow gradually, and hold the wheel straight. On rainy days leave more distance than usual and keep headlights on even in daytime.

Slow down through standing water so you do not splash pedestrians. Afterward, press the brake lightly a few times to dry it. Do not drive into flooded roads; you cannot know how deep they are.

❄️Snow, ice and black ice

• Start off and accelerate gently. If the wheels spin, ease off rather than pressing harder.
• Brake early, gently and in several stages. Slow down before downhill stretches and use a low gear or engine braking.
• Following the tracks of cars ahead is relatively stable. Leave much more distance than on dry roads.
• Black ice is a thin, clear layer of ice that looks like a wet road. It forms especially on bridges, at tunnel entrances and exits, in shaded areas, on mountain passes, and early in the morning and at night.
• Slow down before bridges and shaded sections, and keep braking and steering to a minimum on them.
• If heading to snowy areas, prepare winter tires or snow chains, and practice fitting the chains beforehand.

🌫️Driving in fog

In fog, turn on low-beam headlights and fog lights so others can see you. High beams reflect off the fog and make it harder to see. With visibility of 100 m or less, you must drive at no more than 50% of the maximum speed.

Drive slowly using the taillights ahead and lane lines as guides, and avoid lane changes and overtaking. If you can barely see, waiting at a service area or other safe place until the fog lifts is an option. Simply stopping on the road is very dangerous because of the risk of being rear-ended.

🌡️Heat waves and winter car care

• Summer: a parked car gets extremely hot very quickly. Never leave children or pets alone in the car, even briefly.
• Summer: do not leave heat-sensitive items such as lighters, spray cans, power banks or fizzy drinks in the car.
• Summer: check coolant level, air conditioning and tire pressure. Long drives on hot roads put strain on tires.
• Winter: check the battery, antifreeze (coolant) concentration, winter washer fluid and wiper blades.
• Winter: check tire wear. Replace tires when the tread depth nears 1.6 mm (the wear indicator). Pressure drops in cold weather, so check it often.
• Winter: before setting off, clear snow and frost from all windows, mirrors and the roof. Roof snow blows off while driving and endangers cars behind.

💬FAQ