The Sydney-Newcastle Freeway (F3) is planned as the principal road link between Sydney, the Gosford-Wyong area, and Newcastle. It will also form part of the inter-capital-city route for the National Highway between Sydney and Brisbane. The F3 has been constructed from Berowra to CaIga and construction has commenced on the Ourimbah to Wallarah Creek Interchange (north of Wyong) section. At present, highway travel between CaIga and Ourimbah is via the winding Pacific Highway which passes through the City of Gosford, or via the more circuitous Peats Ridge route. The level of traffic service is low on both highways and, because of the increasingly high traffic volumes encountered in the area and the capacity constraints on these highways, a freeway is required. The Commonwealth Government and the States are co-operating in the development of a declared system of National Highways. In reviewing funding allocations, the Commonwealth Department of Transport has nominated the Mt. White/Calga — Ourimbah section of National Highway as a high priority work. The project involves the construction of 21.3 kilometres of six- lane, dual carriageway road with interchanges at CaIga, Kariong, Somersby and Ourimbah, five million cubic metres of earthworks, the employment of a probable workforce of 350 persons, and eighteen bridges. The largest bridge, required for crossing Mooney Mooney Creek, will be 480 m long and have a waterway clearance of 73 m. This section of the proposed Freeway has a particularly high benefit/cost ratio (4.9/1) . It will reduce the travel distance on the Calga-Peats Ridge-Ourimbah route by 11.6 kilometres while reducing the travel distance between CaIga and Kariong by 4.8 kilometres for Gosford travellers. In compliance with the environmental policies of both the State and Commonwealth Governments, the Department of Main Roads, N.S.W., has undertaken comprehensive investigations into the environmental effects of the preferred route for the Freeway and of feasible alternatives. This Environmental Impact Statement presents particulars of these investigations.