Saudi Arabia's newest megaproject is the Riyadh Metro

The construction of a metro system for the Saudi Arabian capital Riyadh will cost a total of $22 billion and will begin early this year. The government expects trains to be running along its six lines by 2019. Work on the tunnel for the first line of the Riyadh Metro is expected to start in two months with the arrival of the spare parts of the tunnel boring machine (TBM) imported from Germany.

The president of the Arriyadh Development Authority (ADA) Ibrahim bin Mohammed al Sultan said the Riyadh Public Transport Project will be "a major driver of employment and economic development". He called it a "cornerstone" that would "enhance the quality of life" for Riyadh's population of nearly six million.

With more than 180 kilometres of track, the Riyadh metro will dwarf the one that can be found in neighbouring Dubai. According to experts, the Saudi government has long considered Riyadh as being the potential capital of a unified Gulf region that would incorporate the six nations of the Gulf Cooperation Council (GCC).