In July 2013 Arriyadh Development Authority (ADA) awarded three turnkey design-and-build contracts for the construction of the city’s 176.7km driverless metro network, which is being built at a cost of $US 23bn. Commercial services are due to begin next year. A full description of the Riyadh metro project can be viewed here. For detailed data on metro projects around the globe, subscribe to IRJ Pro.