The empty seats in a packed Seoul train, and who they wait for

Board a Line 2 (2호선, i-hoseon) train at Gangnam (강남) around six in the evening and the car fills the way a tide comes in — bags against backs, one hand on the pole, faces angled at nothing in particular. Then your eye reaches the ends of the carriage. Three seats in each corner sit empty, upholstered a shade off from the rest, while a dozen people stand over them and never look down. That deliberate gap, in a crush where no other space exists, is the first rule of the Korean carriage that a first-time visitor almost always breaks.

The seats that stay empty

They are called 교통약자석 (gyotong-yakja-seok), the "transit-vulnerable seats," though older riders still say 노약자석 (noyakja-seok), the seats for the old and the infirm. Every subway car has them clustered at both ends, six to a car, set apart by a cooler upholstery and a run of pictograms above the window: a figure with a cane, a wheelchair, a rounded belly, an adult holding a child. The signage repeats itself in Korean and English, but the sign is not really the instruction. The instruction is the empty seat itself.

What throws a visitor is that the seats stay open even when nobody who needs them is aboard. In most cities a free seat is an invitation; here it is a reservation held for a person who has not yet boarded. Part of the reason is arithmetic — riders aged sixty-five and over travel the Seoul subway free under a courtesy scheme called 경로우대 (gyeongno-udae), so an elder may step on at any stop, and the seat has to be there when they do. You keep it in reserve the way you would keep an aisle clear.

The pink seat and the badge that speaks first

One seat in the row is painted an unmistakable pink. This is the 임산부 배려석 (imsanbu baeryeo-seok), the place set aside for pregnant riders, introduced across Seoul's lines in 2013 and kept empty on a stricter principle than the rest. The logic is that early pregnancy is invisible; a woman ten weeks along looks like everyone else on the platform, and the custom holds that she should never have to announce herself to claim a chair. So the pink seat waits, conspicuously vacant, in cars where every other inch is taken.

To close the gap between an invisible condition and a public seat, the city hands out a small pink 임산부 배지 (imsanbu baeji), a badge riders clip to a bag strap. You can pick one up free at station offices and at district public-health centres (보건소, bogeonso). It does the asking so the wearer does not have to, and it is why you will see a seemingly unremarkable commuter settle into the pink seat while a standing crowd simply lets her.

No one enforces it, everyone obeys

There is no conductor walking the aisle to police any of this. The rule holds through 눈치 (nunchi), the Korean habit of reading a room and adjusting before anyone speaks — the same instinct that tells you when to lower your voice or refill a neighbour's cup. Sit in the corner seats and you will feel it as a change in the air: a held glance, a grandmother who plants herself directly in front of you rather than take a middle seat, occasionally a quiet word. The correction rarely arrives as confrontation. It arrives as being visibly, collectively noticed.

An empty seat in a full train is not an oversight. It is a space being saved out loud.

The same grammar runs through the city buses, where the front seats nearest the driver carry the same pictograms and the same expectation. On a green neighbourhood bus climbing a hill in the late afternoon, those front seats stay open past a dozen standing passengers, because the person they are for might board at the next stop with a cane and a bag of groceries. The contract works because breaking it in public costs more than standing does.

노약자석은 비어 있어도 앉지 않는다 — 그 자리는 아직 오지 않은 사람의 것이다.

How to ride without giving offence

The practical version is simple. Stand or sit in the long middle rows, which are open to anyone, and leave the two end clusters and the pink seat alone unless you genuinely qualify. Since late 2023 a single ride starts at ₩1,400 on a rechargeable T-money card, sold at any station machine and every convenience store; trains on the main Seoul lines run from around 5:30 in the morning to near midnight, with Line 2's green loop among the last to stop. If you want a seat at all, ride after ten in the morning, once the Gangnam and Sillim (신림) crush has thinned.

The one mistake to avoid is the tired traveller's reflex: dropping into the pink seat because it is the only open one in the car. It reads not as fatigue but as a small refusal to see, and it is the fastest way to feel a carriage turn cool around you. If you are already seated in an ordinary row and an elderly rider boards into a full car, the graceful move is to rise before being asked and step toward the door — the offer made quietly, the way the whole system prefers.