Japanese superstitions, Number 4 and a city without the tramway 4

The superstition of Number 4 has a long history in Japan, coming from the fact that 4 is pronounced shi, a homonym for "death". As I wrote before, the number 4 is rarely used to number a room, gifts should never be made of 4 pieces, and I was accommodated in hotels where 4 was skipped in the floors numbering.

Recently, while visiting Matsuyama, Ehime, I noticed that the tram route 4 is also missing, the city's tramways being numbered 1,2,3... 5 and 6.