The Tashkent metro earlier this month announced a significant reduction in the speed of trains, if not completely stopping them due to the heat. This, as I understand it (the message does not directly mention this), is about the ground part of the metro, which makes up a significant part of it. Recall that the heat in Tashkent lasts at least three months a year, often much longer.
The Tashkent metro explains that, in accordance with the rules for its use, when the temperature on the rails exceeds +55 ° C, the speed of trains decreases, and when the temperature on the rails reaches +60 ° C, the speed of trains is limited to 40 km / h, and at a temperature on rails +65 °С, train speed should not exceed 25 km/h. When the temperature on the rails is +70 °C or higher, the movement of trains is limited.
In other words, the skytrain must slow down when the air temperature reaches +29°C, is limited to 40 km/h at 34°C, is limited to 25 km/h at 39°C, and stops at an air temperature of 44°C.
How did I get this data? As a result of a short search on the Internet. Read more in the Russian version of the story.