World's longest driverless metro launched in Saudi Arabia

In Saudi Arabia, the world's longest driverless metro has been launched - it consists of 85 stations and six lines, covering 176 km of the country's capital Riyadh. The system will operate 183 fully driverless trains with carriages from Germany's Siemens, Canada's Bombardier, and France's Alstom, and the project cost amounted to $35 billion.