One of the new proposals calls for a combination road and rail link from Karatsu on Kyushu Island and terminating at Busan, the second largest city in South Korea.[1] Of the three tunnel routes under consideration, the favoured design was a combination bridge from Karatsu to Iki Island, followed by a 60 km tunnel to the central portion of Tsushima Island, and then a 68 km tunnel roughly westward to Busan at an estimated cost of approximately 10 to 15 trillion yen ($111 billion to $157 billion).[9]