This is a remarkable feat. Amazing.
I’d like to add an interesting metric: density of subway/metro stations as measured by number of stations per square kilometer.
In European cities,
City,
Metro System,
Stations,
City Area (km²),
Density (stations/km²):
1. Paris,
Metro de Paris,
244,
105,
2.32
2. Berlin,
U‑Bahn only,
173,
892,
~0.19
3. London
Underground (London Tube),
~270,
1,572,
~0.17
4. Madrid,
Metro de Madrid,
~300,
605,
~0.50
Paris takes the lead, not just in Europe but globally, with ≈2.32 stations/km². Madrid has a dense network too (≈0.50), though well behind Paris. Berlin (U‑Bahn only) and London have much lower densities (~0.17–0.19). Rome’s iconic metro is relatively sparse in terms of station density compared to other major European and Asian cities.
Here’s how European and Asian cities stack:
1. Paris (~2.32 stations/km²)
2. Seoul (~1.27)
3. Madrid (~0.50)
4. Tokyo (~0.46)
5. London (~0.17)
6. Berlin (~0.19)
7. Hong Kong (~0.09)
8. Shanghai (~0.06)
9. Rome (~0.057)
Seoul is highest among major Asian metro systems in terms of station concentration, making it the city in Asia with the densest metro network per square kilometer. Seoul has 768 stations in its metropolitan subway system spread across the city proper area of 605 km². By comparison, Tokyo’s combined metro (Tokyo Metro + Toei) has around 286 stations over ~621 km, giving a density of about 0.46 stations/km². Beijing has 523 stations but the city covers about 16,411 km²—yielding a much lower density (~0.03 stations/km²). Shanghai’s figure fluctuates due to rapid expansions: 409 unique stations from early 2025 data.
In addition to density, another interesting metric is
the number of street-level entrances (exit/entry points). Counting just stations ignores how many access points are available to the public. More entrances = better coverage, shorter walking distances, improved accessibility, especially in dense urban zones. Examples from Paris are:
Saint‑Lazare station (Lines 3, 12, 13, 14) has 11 entrances. Hotel de Ville (Lines 1 & 11) has 7 entrances. Madeleine station (Lines 8, 12, 14) has 5 accesses with 7 separate entrances. Alesia station (Line 4) has 6 entrances. Opera station (Lines 3,7,8) has 3 main entrances.
On average, Paris Metro stations have approximately 3–6 street-level entrances, with major hubs having 7–11. Paris doesn’t just have many stations, it maximizes them with multiple entry points, making its system exceptionally accessible over its territory.
Seoul also scores similar in accessibility due to its exit-rich stations, especially in dense areas. Other major metros (Tokyo, Madrid, London) lag when entry points are factored in.
I did not include US cities but I believe New York City might be notable.