The major interstate freight routes are the Main Southern and Main North lines, with the Illawarra and Main Western lines serving lineside industries and as alternate interstate routes. In the inner city area the Metropolitan Goods lines connects major freight terminals to the main passenger lines and the Southern Sydney Freight Line which runs parallel to the Main South line from the western end of the Metropolitan Goods lines to a point beyond the end of suburban services. As of 2013, construction of the Northern Sydney Freight Corridor is under way. This is a series of projects along the Main Northern line between Sydney and Newcastle aimed at increasing the number of freight trains operating along the route.