The Eccles-Pole Moor section opened in 1971. Between Eccles and Pole Moor, 67 motorway crossings were required, including seven viaducts and eight junctions. Much of the Worsley Braided Interchange was built on undeveloped mossland where deep peat deposits had been covered with waste. Between Worsley and Milnrow, some underlying coal seams were still actively worked when the motorway was constructed and allowances had to be made to counteract possible future subsidence. The motorway crosses the Irwell Valley and the Pendleton Fault on a single-span bridge above the river.