Frequently asked questions

As a tunnel has been selected as the best option for the highway upgrade through Blackheath, duplication of the existing highway through Blackheath is no longer being actively progressed by Transport for NSW.  

While we progress plans for a tunnel, Transport for NSW is inviting feedback from the Blackheath community on short-term improvements that could be made to the existing highway to improve safety, amenity and connectivity in Blackheath.

Community input and the further development of the Strategic Business Case will guide the development of any further work on this route

We have identified three possible locations for tunnel portals:

• a northern portal near the Mount Boyce Heavy Vehicle Safety Station;
• a southern portal south of Evans Lookout Road;
• and a shorter southern tunnel portal at Sutton Park.

The proposed tunnel entry south of Evans Lookout Road would have an impact on a section of National Park and Sydney Water catchment area. 

The proposed entry at Sutton Park would have an impact on recreational land and residential properties at the end of Evans Lookout Road, Brightlands Avenue and Chelmsford Avenue. Transport for NSW is speaking directly with any potentially affected property owners.

The proposed portal at Mt Boyce Heavy Vehicle Safety Station may impact access to the picnic area and may also require relocation of the scar tree (which has been moved previously).

The long tunnel portal would impact a portion of Blue Mountains National Park area near Evans Lookout Road. None of this land is part of the Greater Blue Mountains World Heritage Area. Most of the affected land is already allocated as residential lots, although no properties have been constructed yet.

The land proposed to be resumed from National Park would also include space to capture and treat water runoff from the Highway. This will allow us to ensure that water released into the National Park is suitably treated to avoid pollution and soil erosion. Treatments could include things like gross pollutant traps, settlement basins and detention basins.

Further technical studies are needed to determine the exact placement of tunnels and tunnel entries. The proposed locations are in areas where the ground is rising. This slope would help to achieve the right depth for a tunnel while minimising above ground impacts. The locations have been chosen to minimise potential property impacts as much as possible.

A tunnel would deliver many benefits for Blackheath:

• Less congestion
• Through traffic moved underground
• Improved urban amenity and connectivity
• Safer town centre for cyclists and pedestrians
• Alternate routes for emergency services
• Giving back the Great Western Highway to the local community.

We are taking the time to plan this project properly and make sure that we have a strong foundation of community consultation for any option selected, in order to choose what is right for the community and road users. Each proposed tunnel portal has a different set of impacts, and Transport for NSW seeks to understand these in greater detail through community feedback.

The short tunnel would require the acquisition of 12 properties on the ends of Evans Lookout Road, Brightlands Avenue and Chelmsford Avenue, and the long tunnel portal would impact on National Park and the Sydney Water catchment area.

We are seeking your feedback to determine what is important to you.

As in the draft designs, a service road would be constructed parallel to the highway that links those streets together. Access to the highway is currently shown at Valley View Road. We have already had feedback from the community that this single point of access may not be suitable; should the Sutton Park portal be chosen as the preferred option, further design work will be undertaken to improve the connectivity of this area of Blackheath to the highway.

Further technical studies are needed to determine the exact alignment of the route underground.

A long tunnel route option, between the proposed Evans Lookout Rd location and the Mt Boyce Heavy Vehicle Safety Station would provide a 4.5 kilometre underground bypass of Blackheath.

A shorter tunnel, between the proposed Sutton Park location and Mt Boyce Heavy Vehicle Safety Station would be approximately 4km in length.

Early investigations indicate a tunnel can be constructed at an average depth of 30 - 40 metres below the surface; the height of a 10 storey building.

The number of lanes in the tunnel and any shoulder width has not been decided. The information provided here is therefore based on the greatest likely width of the tunnel construction.

The width of the tunnel access construction footprint at the portals is unlikely to be greater than 60m including roadway, construction access, spacing between the tunnel tubes and retaining walls. This figure would reduce as the tunnel moves form a cut and cover structure to a bored tunnel. Where the tunnel is at its deepest, from western-most outer wall (the slow lane wall north/west bound) to eastern most outer wall (the slow lane wall south/east bound) is likely to be less than 40m. These figures may change locally dependent on the geology.

A tunnel will require the construction of some above ground buildings such as an Operational Control Room, water tanks for fire suppression and electrical sub-stations. The location of these structures is yet to be investigated; these are often built near tunnel entrances.

Ventilation outlets, sometimes referred to as ‘stacks’, are designed to take tunnel air up away from populated areas around tunnel portals.

The shorter tunnel option may require ventilation outlets. However, proposed portals for a longer tunnel are located away from where people live and work, which may mean ventilation outlets are not required. Further studies are required to determine the ventilation needed for either of the tunnel options.

There is no intention to make this a tolled road.

We have already received feedback regarding the importance of surface features such as hanging swamps, as well as underground water features such as aquifers in the area.

We are committed to minimising impacts on the environment, including groundwater sources, and will develop an option with minimal interference. A full assessment of impacts will form part of the Environmental Impact Statement.

As with any construction project, there will be some noise and vibration impact when work is being undertaken. Transport for NSW will be in contact with residents throughout the planning process and construction.

Independent reporting will be carried out on all properties deemed to be potentially impacted by tunneling works, including vibration. However, given the depth of the tunnel, impacts are likely to be minimal.

Where damage has occurred it is typically within a short distance from the tunnel alignment (less than 50m). The Contractor is obliged under the planning conditions of approval to rectify any damage caused by tunnelling within six months of completion of construction.

The upper strata of the Blue Mountains - the peaks and ridgelines - are predominantly made up of a number of sandstone and claystone layers with come localised basalt caps on higher peaks.

These layers are visible on the cliff faces, and this is the expected geology through which a Blackheath tunnel would be constructed. While most sandstone and claystone layers are expected to be good tunnelling media, the Banks Wall sandstone is known to have some unusual characteristics which will require some focus.

Further geotechnical surveys and investigations are required to determine the best path for a tunnel underneath Blackheath. Investigations to date have given no indication that a tunnel is not feasible underneath Blackheath.

Transport for NSW will investigate a suitable location to reuse any material extracted during construction. The method for the removal of material, and the minimisation of impacts on the local community, would form part of the environmental assessment.

A Transport for NSW Policy is currently being developed to inform whether any dangerous goods would be allowed through a Blackheath bypass tunnel. Preliminary studies indicate that around 4% of daily current heavy vehicle movements in Blackheath are dangerous goods.

At this stage heavy vehicles will not be mandated to travel through a Blackheath bypass tunnel, and it is yet to be determined whether vehicles carrying dangerous goods will be allowed through a tunnel.

However unless those drivers have deliveries or are picking up goods within the Blackheath township it will be faster for them to choose to travel through the tunnel.

The strategic business case is looking carefully at the needs of all road users across the corridor, alongside the program’s objectives. Our early investigations have shown that nearly 40 per cent of road freight in the Blue Mountains either begins or ends its journey between Katoomba and Lithgow. Alongside this, our traffic modelling shows a large number of vehicles entering and exiting the Highway between Katoomba and Mount Victoria. We need to ensure that any tunnel addresses the service needs for this traffic.

The NSW Government must carefully balance its choices of investment across all government portfolios. Transport for NSW is cognisant of this and as such, in areas where the surface road is suitable for upgrading, designs will be progressed that utilise the existing route.

The NSW Government has committed $2.5 billion towards upgrading the Great Western Highway between Katoomba and Lithgow. Partial or staged funding of a project of this size is common and the team is working to develop the project and will seek additional funding as required. The construction cost of a tunnel will depend on the final alignment, depth and length and is still to be determined.

The construction of a tunnel option could take up to four years from construction contract award to opening date.

The NSW Government has ruled out any impact on the Greater Blue Mountains World Heritage Area.

The proposed outermost southern portal would impact on a section of the National Park. A full investigation of these impacts and mitigations would form part of the environmental assessment.

The final tunnel design would include many safety systems and equipment to deal with incidents. These include visual and audible communication systems; emergency escape passages; access for emergency services vehicles; a water deluge system to suppress fire, and emergency smoke extraction systems. Communications systems and CCTV are used to monitor tunnel activity and respond to incidents as they occur.

No. Cyclists would not be able to use the tunnel, but the existing Great Western Highway route will remain and the tunnel will remove through traffic and trucks from the town, improving safety for pedestrians and cyclists.

The proposed tunnels would be designed to the highest safe speed possible, with a 80 km/h posted limit.

The NSW Government has committed $2.5 billion towards upgrading the Great Western Highway between Katoomba and Lithgow. This includes planning for projects such as Blackheath and delivery of other sections of the 34km project.

The long term upgrade of the Great Western Highway has already seen the duplication of 50 kilometres of highway from Emu Plains to Katoomba. Once completed this Program will complete the missing 34kms to see an approximate 90km duplication from Emu Plains to Wallerawang.

A tunnel from Penrith to Lithgow would be three times longer than the longest road tunnel currently in the world. Building and operating a tunnel of this length would be prohibitively expensive.

Additionally, a tunnel under the mountains would only divert the traffic that is actually travelling all the way through the mountains. Traffic modelling shows a large number of vehicles entering and exiting the Highway between Katoomba and Mount Victoria, and nearly 40 per cent of the road freight moving between Katoomba and Lithgow, including refrigerated goods, fuel, commercial and retail goods, either begins or ends its journey within the Blue Mountains, supporting the local economy. The local nature of this traffic and freight means that a longer tunnel wouldn’t address the existing needs of traffic on the corridor.

The Upgrade Program will address known safety issues between Katoomba and Lithgow; improve intersections, straighten curves and reduce gradients to provide a safer road for both local and through traffic. Upgrading the existing highway will improve congestion and provide more efficient and reliable journeys for all road users travelling in, around and through the Blue Mountains. The upgrade will also improve access for pedestrians and cyclists, as well as provide greater resilience in times of emergency and extreme weather.

The NSW Government is committed to moving more freight from road to rail and is investing in the rail freight network to increase capacity. The NSW Government has also committed to investigate improvements to the rail corridor for commuters through the Faster Rail strategy. 

The rail line provides a reliable service for Blue Mountains commuters; however, the highway will remain a vital link for the Central West and the Blue Mountains and there is no substitute for upgrading the highway as we need both road and rail to meet current and future demand.

Around half the freight in the Blue Mountains is carried by road, including refrigerated goods, fuel, livestock, commercial and retail goods. Much of the freight currently on the road network requires direct access to freight hubs, such as retail precincts, light industrial areas or home deliveries.

The Great Western Highway is an important route identified as part of the Land Transport Network (Roads), which has been developed through collaboration between Commonwealth, State, and Territory governments. It details the road and rail routes connecting economic hubs.

The Great Western Highway is one of four major freight connections into Sydney from the regions and is the key east-west route. However, it is the only route limited to 19 metre B-Double and 20 metre Performance Based Standard (PBS) vehicles.

Alternative routes around the Great Dividing Range use either the M1 or the Golden Highway and are up to 100 kilometres longer.

This upgrade looks to open up access to more productive vehicles as well as improve more safety and travel time for commuters and tourists.

The NSW Government continually investigates potential transport options and corridors across the state and has identified many of these within the NSW Future Transport 2056 document.

Based on transport studies and investigations, the Great Western Highway is the key corridor for transporting goods and people from the Central West to Sydney. Funding has been prioritised for the Great Western Highway to plan and deliver the upgrade of the highway between Katoomba and Lithgow. 

Upgrading the Bells Line of Road remains a long term option for the NSW Government.

The corridor between Mount Victoria and Lithgow was reserved and placed in the LEPs of the Blue Mountains City and Lithgow City councils in 2013.

The upgrade program for Katoomba to Lithgow was announced in 2019 and a period of consultation undertaken in November and December. We are still in the very early stages of planning and design of the corridor between Katoomba and Mt Victoria.

Community feedback is vital in shaping the program, and alongside further investigations and studies, will help us to determine the final route for the Highway Upgrade.

The NSW Government has progressively upgraded sections of the highway to make it safer and more reliable with the most recent project at Kelso opened to traffic in March 2017. In 2018, $30 million was announced to upgrade the highway between Kelso and Raglan.

There have already been important safety improvements delivered through the safety upgrade program along the Great Western Highway at Blackheath, Mount Victoria and Forty Bends. This work has seen improved road surfaces, intersection upgrades, and lane widening delivered as part of the $250 million investment by the Australian and NSW governments.