The Isfahan–Shiraz railway, part of the Tehran–Bushehr–Asaluyeh national corridor, spans approximately 500 Km. Of this, 130 Km have been designed and supervised by Iran Oston Consulting Engineers, with operations commencing in 2009.

One of the most critical sections is the Kulikash bottleneck, where four tunnels have been constructed to navigate challenging terrain. Due to the strategic importance of the Isfahan–Shiraz railway, Iran Oston Consulting Engineers was also entrusted with the supervision of pavement, signaling, and communications systems throughout the project.