Newly released models continue to be wider than their predecessors, the combined result of electric-vehicle battery packs, stricter crash standards and a preference for large SUVs.

Parking bay dimensions, by contrast, have barely changed. A wider car in the same bay leaves less clearance, and doors increasingly touch the vehicle alongside.

There is a pedestrian dimension too. As width and front-end height grow together, the blind zone from the driver's seat widens, and the stretch in which a child disappears from view lengthens.

The lag between standard and reality

Bay dimensions are set in regulation, and changing them means re-marking existing facilities. In underground car parks of finished buildings, column placement makes adjustment difficult.

Some operators respond by increasing the share of wide bays. Drawing fewer bays in the same area, however, reduces total capacity.

The practical responses are simple: reverse in to widen the space for getting out, open doors in two stages, and let children out toward the pavement rather than around the front of the car.

Parking is tightest in Korea's older commercial districts. Where shops front narrow lanes—as in the Chinese-Korean business areas of Incheon and Seoul—vehicle width quickly becomes a question of trade.