Berlin U-Bahn : Germany

The Berlin U-Bahn (from “Untergrundbahn”, meaning “underground railway”) is a rapid transit railway in Berlin, the capital city of Germany, and is a major part of the public transport system of the city. Designed to alleviate traffic flowing into and out of central Berlin, the U-Bahn rapidly expanded until the city was divided into East and West Berlin at the end of World War II. Although the system initially remained open to residents of both sides, the construction of the Berlin Wall and the subsequent restrictions imposed by the East German government limited travel across the border: The East Berlin U-Bahn lines were severed from West Berlin; while two West Berlin lines that ran through East Berlin (U6 and U8) were allowed to pass through without stopping.

 

Assessments: furthermore, you can use every mobile phone network while on trains or in stations. You can also top up your mobile phone at all of BVG ticket machines. Fastest way to get around the city. this is from experience. Getting around is also extremely easy since the way the map is laid out there are minimal amount of lines and laid out as simple as possible with little waiting time. I would know to export this idea to other countries would be very dangerous and disruptive especially to countries that already have established underground systems but a few of them are failing and if some things broken its should be fixed.