Why is the Swiss Glacier Express the slowest train?

Because this train is 300 kilometers long and takes about 7.5 hours, the average train only takes 2 hours.

On June 25th, 1930, the first train named "Glacier Express" traveled from Zermatt, Switzerland to St. Moritz, with a total distance of 300 kilometers and a 7.5-hour drive, so it was called "the slowest landscape train in the world". The glacier in the name refers to the Rhone glacier adjacent to Gretchen village. This glacier, once the largest in Europe, has become the fifth largest glacier in Switzerland due to global warming. On the way from Zermatt to St Moritz, the glacier train will cross the Alps, 29/kloc-0 bridges, 9/kloc-0 tunnels and the Oberup Pass, the highest point of which is 2033 meters above sea level. Narrow-gauge railways are used for the whole line, and some of them use toothed rails to drive on steep slopes.