Turkish Prime Minister Recep Tayyip Erdogan inaugurated the first metro line on the Asian side of Istanbul on Friday, saying that Turkey will build subways.

Stressing that the line would make a huge contribution to Turkish economy, Erdogan said "if Kadikoy-Kartal line is not constructed, 32 additional buses and 67 minibuses would have to run every year between Kadikoy and Kartal. However, he said, "we are expecting withdrawal of 572 buses and 1,227 minibuses from the traffic that allow a huge relief."

The 21.8-km-long subway between Kadikoy and Kartal has 16 stops, taking 32 minutes. It' has a daily capacity of 700,000 passengers.

The line is equipped with Thales Seltrac CBTC and has a design headway of 90 seconds with a service headway of two minutes. Services are operated by a fleet of 30 six-car trains supplied by CAF.

The total cost of the project was 751.3 million euros. A 3.4-km extension to Kaynarca is currently under construction.

Istanbul's Mayor Kadir Topbas stated that the line is projected to carry 5 million passengers in 2014 with a length of 230 kilometers, and the number of passengers is expected to increase to 7 million in 2016.

According to a census in 2011, Istanbul had a population of 13, 624,000.