When the first train left Helwan station in April 1987, the platform signage was already twenty months behind schedule. The French contractors had specified a clean sans for every station name, but the Arabic — set in a naskh hand — arrived separately on tracing paper. The tilers improvised. In the end, the misalignment became the system: Latin on the left, Arabic on the right, twelve millimetres between them.
Line 1's red — the colour of the roundel — functions as both identity and instruction. A commuter descending into Sadat station does not need to read the line number. The red band on the platform edge, the red ticket machines, the red circle on the network map: they form a single continuous signal. Colour precedes language. Shape precedes colour. And the roundel, that red circle with the white bar, is the most durable piece of graphic design in the Arab world.