Great Western Highway - Upgrading Since World War 2

Upgrading Since World War 2

In 1957 a short deviation immediately west of Linden eliminated two narrow overpasses of the railway, both of which had right angle bend approaches from both directions. These bridges would have had to have been replaced in any event, as were most of the other railway overpasses between Penrith and Mount Victoria, to allow for overhead wiring for the electrification to Lithgow of the Main Western Railway.

In 1958 the 'Forty Bends’, where the Highway runs along the foot of Hassans Walls approaching Lithgow, were eased. The fact that this section of the Highway is on the southern side of a very high escarpment poses severe ice problems during winter, due to the lack of sunlight.

In the early 1960s the highway was deviated east of Leura to cross under the railway at Scott Parade (which was itelf part of the former highway route) and run along the north side of the railway to rejoin the previous route at Leura Mall.

In 1967, the highway was deviated to bypass Springwood shopping centre, eliminating two narrow underpasses of the railway from the highway route. The previous route remain in use for local traffic.

In 1968 a dual carriageway 3 km deviation was opened at Prospect. This replaced the only winding section of the Highway between Parramatta and Penrith.

From the late 1960s to the early 1970s the highway was almost entirely realigned and constructed to three lanes, being deviated as necessary, between Kirkconnell and Glanmire. Ironically this included reinstatement of most of the parts of Major Mitchell's 1830 alignment which had been deviated in 1929 to ease gradients.

This work was extended eastward to Mount Lambie in stages during the late 1980s and early 1990s. A second Cox's River deviation, to replace the 1929 deviation, was completed in 1993, between Marrangaroo and Mount Lambie.

At Katoomba the highway was deviated in 1985 to travel along the eastern side of the railway station, whereas the original alignment crossed the railway via a level crossing at the north end of Katoomba St and ran along the western side of the railway. Immediately west of where the highway now crosses the railway due to this deviation, the highway was realigned over a distance of 1 km in 2004 to remove the sharp bend at 'Shell Corner'.

In Bathurst, the Denison Bridge (1870) was bypassed in 1991 by a realignment of the Highway where it crosses the Macquarie River into Bathurst city centre. Because of its heritage value it was retained for use by cyclists and pedestrians.

During 1991-1993 a massive cutting was made to improve and widen the alignment of the highway immediately east of Woodford. At the top of the southern side of this cutting can be seen the rudimentary excavation of the rock for Cox’s 1815 road. This was severed in 1868 by the construction of the Springwood-Mount Victoria section of the Main Western Railway. The railway itself was deviated at this point in the 1920s when it was duplicated, and a cutting on the original alignment of the railway now forms the top section of the southern face of the highway cutting, the terrace in the face of the cutting being the bed of the original cutting.

In June 1993 the highway route was severed at Emu Plains with the closure to road traffic of the Knapsack Gully Viaduct. This occurred in conjunction with the westward extension of the M4 motorway from its terminus since 1971 at Russell Street, Emu Plains. This extension connects directly to the highway at Lapstone, bypassing the viaduct. The portion of the Great Western Highway west from Russell Street to Mitchells Pass Road is now only used by local traffic to access residential properties. Mitchells Pass, travelling is now one way eastbound between Lennox Bridge and the highway, due to its narrowness. Great Western Highway traffic therefore has to use the M4 between Russell St and Governors Drive.

A major realignment west from Mount Boyce (the highest point on the highway) to eliminate the Soldiers Pinch and other nearby sharp curves was completed in 2002.