The Kolkata Metro Line 4 or the Yellow Line, also known as the Noapara - Barasat Line of the Kolkata Metro in India is a 16.876 km (10.486 mi) long metro route from Noapara to Barasat in North 24 Parganas, which is under construction. It is being built by RVNL. It will run mostly underground viaducts. It will run elevated until Jessore Road Station and then it goes underground towards Barasat metro station. It will have an interchange station at the NSCBI Airport with Kolkata Metro Line 6.