Great Western Highway - Route Development

Route Development

Between present-day Flemington and Dogtrap Road (now Woodville Road), Parramatta Road travelled in a wide arc some 2 km south of the present route, in order to avoid marshy areas around Haslems Creek and the Duck River. This was deviated in the 1820s to follow the present route.

At Mount Victoria, at the western edge of the Blue Mountains, the route of Cox's road turned north to Mount York, from where it descended into the Hartley Valley. This pass was the major piece of engineering on the original route, and when Governor Macquarie travelled the new road in 1815, he named it Cox's Pass in honour of the builder. From the foot of Mount York the road resumed its westerly direction to where Hartley now stands.

However from here it ran via the present-day Glenroy, Mount Blaxland, Cut Hill Rd, Pitts Corner, Phils Falls, Mount Olive Rd, Carlwood Rd and Sidmouth Valley to a point 2 km south of O'Connell. From here it continued westward, not crossing the Fish River, but crossing Campbells River 1500 metres north of the present bridge at The Lagoon (Apsley) and ascending to another ridgeline where it turned north to Gormans Hill, to reach the future site of Bathurst from the south, not the east.

For the first one hundred years after this ceased to be the route of the Great Western Road it remained trafficable, but the destruction of the bridge at Phil's Falls on the Fish River in 1930 meant it was no longer a through route, and parts became untrafficable. However, most of this route remains in existence as a series of local roads.

The original route had only been in existence for eight years when, in 1823, Assistant Surveyor James McBrian identified an improved route on the approaches to Bathurst. This route turned north 2 km south of O'Connell to run northwest to where Kelso is now located, then west across the Macquarie River into Bathurst. The section from south of O'Connell to Kelso is now part of the Bathurst-Oberon Road, and from Kelso into central Bathurst still remains as part of the Great Western Highway.

When Major Thomas Mitchell was appointed as Surveyor-General in 1828, one of the first matters to which he turned his attention was the improvement of the Great Western Road. Mitchell’s attention was focussed on providing a more direct and easily graded route for the Great Western Road. To this end, he surveyed a route running northwest from Hartley via Mt Walker to Meadow Flat, crossing the Great Dividing Range at Mount Lambie, then running in an almost straight line westward via Browns Hill to Kelso, to meet the pre-existing road. This road remains in existence - from Mount Lambie west it remains as the route of the current Highway (with deviations) but the section adjacent to Cox's River was inundated by the construction of Lake Lyell for Wallerawang Power Station in the late 1970s.

Mitchell was also concerned to improve the worst sections of the road, which were the climb from the Cumberland Plain, on which Sydney sits, and the descent of Mount York, down the western side of the Blue Mountains.

In improving the eastern ascent Mitchell adhered largely to Cox’s route, which follows the southern side of an east-falling gully to reach the plateau at where Blaxland is now located. However he engaged the Scots engineer David Lennox to build a stone arch bridge across the mouth of a particularly deep side gully, and this bridge is still in use, although it has been restored several times. Some of the original access tracks used by convicts during the initial construction phase of the road still exist as part of an elaborate mountain bike trail network on the eastern side of the escarpment. This route was later superseded by what is now called Old Bathurst Road (although it is not the first route), located to the north of the original route.

After protracted arguments first with Governor Ralph Darling and then his successor Richard Bourke, and ignoring orders, Mitchell surveyed, designed and had built what is now known as Victoria Pass, where the Highway drops from the Blue Mountains into the Hartley Valley. Midway down the road had to be supported on a causeway formed by massive stone buttressed walls, where a narrow ridge connects two large bluffs. This ridge had to be widened and raised to give the highway a route from the upper to the lower bluff. Mitchell cut terraces into the sides of these bluffs to form a passage for the road. It is a testimony of Mitchell’s vision and engineering skill that this route, almost unchanged, and using his 1832 stonework, is still in use. Because this pass brought the road into the Hartley Valley several kilometres south of the Mount York descent, it necessitated a new route as far west as Hartley to meet Cox's road. This also is still in use as part of the highway.

In 1929 the Main Roads Board deviated the route north from Old Bowenfels to Marrangaroo, using trunk road 55 (Mudgee Road). From Marrangaroo a new road was built westward, running south of Wallerawang to meet Mitchell's 1830 deviation immediately east of Mount Lambie. This route avoids the long, steep gradients either side of Cox's River, which were the main drawback of Mitchell's route.

The Great Western Highway today therefore consists of Parramatta Road to Parramatta, the Great Western Road to Emu Plains, Coxs Road to Hartley (other than Mitchell's deviations at Lapstone and Mount York), Mitchell's route from Hartley to Old Bowenfels, the Main Roads Board route from Old Bowenfels to Mount Lambie, Mitchell's road from Mount Lambie to Kelso, and McBrian's road from Kelso to central Bathurst.