The Istanbul LRT (Hafif raylı sistem or Hafif Metro (Light Metro) in Turkish), which consists of the M1 and T4 lines, is a light metro system in Istanbul, spanning a total length of 32 km (20 miles) with 10.4 km (6 mi) of it underground. There are 40 stations, including 12 underground and 3 viaduct stations. Line M1 is in fact a full metro line and no light metro, because it is totally segregated from other traffic, without level crossings, while line T4 has some level crossings. A total of 163 trainsets transport 220,000(M1) and 95,000(T4) passengers per day.