Saudi Arabia is launching one of the world's biggest mass-transit construction programs. On July 29, the Riyadh Development Authority selected three international design-build teams for contracts totaling more than $20 billion for six lines on the new subway system in Riyadh. The development authority plans to compete negotiations regarding the contracts in the next few months.

Extending more than 170 kilometers and including 87 stations, the government-funded program will entail some 600,000 tonnes of steel and over four million cubic meters of concrete. Construction on the metro system is slated to start next year; commercial operations are expected to begin in 2018.