Its history dates back to the beginning of the 20th
century. It is when the idea of building a metro first occurred. It was not clear whether the metro would be electrified or not; the original notion was to employ steam-powered trains. The final plan for electric railways was finally approved in the 1930s. Unfortunately, the World War II and a following poor economic situation interrupted the start of the construction works.
The metro first opened in 1974 and it has been operating ever since. After the Velvet Revolution, a most of previously existing stations were renamed to be politically neutral. The trains of Soviet origin were gradually replaced with the new types of trains. In 2002, the metro was severely damaged by heavy flooding; it was fully restored after almost a year.
Line B (yellow) is the longest of the three with its 25.6 km, while Line C (red) is statistically the busiest one; it transports up to 26,900 people per hour. The Prague Metro
is designed to transport as many people as possible while allowing them to transfer to any of the lines from the line they are currently riding. Line A (green) is the most recently innovated – four new stations were added in 2015.
Even after the 2015 expansion, there are plans for more. The City Hall has come up plans for the construction of Line D (possibly blue), which would connect the centre with southern parts of the city. The project financial plan is now under debate. The new line is expected to open to the public in 2022.