Mashhad Urban Railway is a rapid transit urban rail line in Mashhad, Iran. It is the second rapid transit system in Iran. The project is known by a number of terms, including "light rail" or "light metro" and "urban rail" or "metro", although the system's full-grade separation from traffic and five-minute headway makes it rapid transit. Or qualifies as a "metro" system altogether. The first phase of the Mashhad Urban Railway, known as Line 1, became operational in April 2011, marking an important milestone in the city's transit development. Line 1 is approximately 24 kilometers long and serves major areas of Mashhad, connecting the north-west with the south-east. Over the years, the network has expanded, with additional lines planned to further improve the city's public transportation system.