Riyadh Metro has begun trial run across the red route, Arriyadh Development Authority (ADA) said on Twitter.
The project is expected to be fully operational by the end of 2019, ADA said earlier.
The Riyadh Metro will span 176 kilometers and include 85 stations. A bus network will complement the project with 24 routes, running 1,083 kilometers and stopping at 776 stations.
In 2013, Saudi Arabia awarded an international consortium— comprising Germany’s Siemens, Canada’s Bombardier and France’s Alstom– contracts worth SAR 84.4 billion ($22.5 billion) to build a 300-train metro system in Riyadh.