About the project
This project will widen the Tasman Highway causeways at Midway Point and Sorell, increasing them from two to four lanes. This will include building a second bridge next to McGees Bridge.
The causeways will also be higher to protect them during extreme weather events.
The upgrade will double the amount of space for vehicles, improving traffic flow. It will also include shared walking and cycling paths, and keep access for recreational fishing on McGees Bridge.
This project will tie in with the completed Midway Point Intersection Solution and maximise the benefits of the other South East Traffic Solution projects.
Current situation
In March 2025 the Australian Government issued requirements for securing their environmental approval for both causeway upgrades. The project team is currently preparing to conduct further scientific assessment to meet these requirements.
The design is being tackled in two stages, with the Midway Point Causeway upgrade and the second McGees Bridge being designed, approved, and constructed first.
In parallel we will prepare a submission for the Tasmanian Government to consider adjusting the Pitt Water Nature Reserve to accommodate the Sorell causeway upgrade.
Once approvals are secured, we can finalise and advertise tenders to engage a contractor to build each causeway. Construction will only be allowed when the Tasmanian live-bearing seastars have been relocated to their temporary habitat sites. You can read more about the seastars below.
Community consultation was undertaken between February and March 2025. A consultation report will be published to this page once available.
Timing
It is expected that construction will start in late 2025, once the extensive environmental assessments have occurred and approvals have been gained.
Funding
The Australian and Tasmanian Governments have committed $187 million to upgrade the Tasman Highway to two lanes in each direction along the Midway Point and Sorell Causeways.
Community consultation 2025
Community consultation took place between February and March 2025, closing on Tuesday 11 March 2025.
A big thank you to everyone who took part and shared their feedback with us.
You can still view our interactive map here: engage.stategrowth.tas.gov.au/tasman-highway-duplication-midway-point-causeway
You can also view the designs and videos showing how the changes to the Midway Point causeway may look, below.
A consultation report will be published to this page once available.
Designs and roll plans
Click a link below to view the roll plan and designs for the Duplication of the Midway Point and Sorell Causeways.
Previous community consultation
In early 2022 we asked the community for feedback on upgrading the Midway Point and Sorell causeways.
A copy of the Community Consultation and Feedback report can be viewed here.
Seastars
This is a complex project with a variety of environmental considerations including the presence of:
- an internationally listed Ramsar wetland
- a state listed Nature Conservation Area
- a nationally listed threatened species.
The video at this link explains the environmental studies for this project.
Pitt Water and the rocky banks on the sides of both causeways are home to the live-bearing seastar, a protected species that is only found in south east Tasmania.
For several years we have been working with marine scientists to understand the ecosystem and identify ways to minimise disruption to this complex environment. This included trialling the temporary housing of seastars in aquariums and outdoor locations.
Based on this detailed scientific work, we now know that it is possible to move seastars away from the causeways during construction, and then return them after upgrades are completed.
Temporary habitat sites have been built to support the large number of seastars that will be relocated before the proposed roadworks.
This detailed scientific work takes time, but it is an important and necessary part of our environmental approvals, and we are committed to limiting the environmental impacts on this unique ecosystem.
FAQs
Current as of February 2025
What is the South East Traffic Solution?
The South East Traffic Solution will help improve travel time reliability through a more efficient and safer road network between Hobart and Sorell and the Southern Beaches.
There are six projects as part of the South East Traffic Solution, four of which have already been completed. These are:
- Arthur Highway Overtaking Lane: an overtaking lane has been constructed on the Arthur Highway south of Iron Creek Bridge
- Sorell Southern Bypass: a bypass has been built between the Tasman Highway near Giblin Drive intersection and the Arthur Highway near Nugent Road
- Midway Point Intersection Solution: the Tasman Highway roundabout at Penna Road has been replaced with a signalised intersection
- Hobart Airport Interchange: the Tasman Highway roundabout at Holyman Avenue and Kennedy Drive has been replaced with a new highway bridge (flyover), ramps and roundabouts, safely separating highway and airport traffic and allowing highway traffic to pass this area at higher speed.
Two projects remain which are currently undergoing design, environmental assessments and approvals. They are:
- Upgrade of Midway Point and Sorell Causeways: widening both the causeways to make them four lanes – two in each direction and constructing a new bridge to the north of the existing McGees Bridge.
- Hobart Airport to Midway Point Causeway: increasing the highway to four lanes – two in each direction.
For further information about these projects, please refer to the project webpage: www.transport.tas.gov.au/sets
Why are you upgrading the causeways?
Upgrading the causeways will provide the following benefits:
- improved traffic flow: four lanes across both causeways will improve travel time reliability for commuters and tourists travelling between Hobart and the south-east region
- improved safety: four lanes, with wider lane widths and safety barrier between the east and west bound traffic across the causeways will reduce the risk of head-on crashes
- the causeways will be built higher, which will keep the causeways open and protect road users during extreme weather events
- the current causeway embankments will be removed and built in new positions with new rock on a gentler slope, meaning they will last for many years to come
- a new and upgraded shared use path will be built for people who walk, wheel and ride.
What options have been considered?
Five options were considered for the Midway Point and Sorell Causeways upgrade during the scoping phase of the project. Each option provided two lanes in each direction between Cambridge and Sorell.
The five options were assessed according to travel speeds and travel time reliability, environmental constraints, costs and social impacts.
A further six sub-options were also considered for Sorell Causeway, after the preferred option was identified. These were assessed according to cost, project delivery duration, complexity of environmental assessments and environmental impacts.
The Midway Point Causeway upgrade will be mostly built to the south of the existing causeway, with an additional two lanes connecting to a new bridge north of the existing McGees Bridge. The Sorell Causeway upgrade will be built to the north of the existing causeway.
What will happen to the existing causeways?
In some locations the existing Midway Point and Sorell causeways will become part of the upgraded causeways and other sections will be removed. We are investigating the existing causeway materials and will reuse as much material as possible in constructing the new causeways.
Particular attention will be paid to ensure protection of the Tasmanian live-bearing seastar habitat before, during and after construction.
What is the cost and timing of the project?
The Australian and Tasmanian Governments have committed $187 million to upgrade the Tasman Highway to two lanes in each direction along the Midway Point and Sorell Causeways.
We’re starting by focussing on the Midway Point Causeway and McGees Bridge upgrade:
- November 2024 – Submitted an application (Referral) to the Australian Government to start its environmental approval assessment process
- Mid 2025 – Finalising designs
- Mid 2025 – Submitting Development Applications and requesting Council Planning Permits
- Mid 2025 – Applying for State Government environmental approvals
- Late 2025 – Construction to start (subject to environmental and planning approvals)
Why is it taking so long?
The project area is a sensitive environment and habitat for migratory shorebirds and the threatened Tasmanian live-bearing seastar, so we are doing extensive environmental studies to understand the impact of the project on this unique and important ecosystem. Our environmental studies will support applications for Commonwealth and State approval processes and help to inform the project’s design.
Management of the ecosystems that are impacted by our proposed roadworks needs to be approved through the Australian Government’s Environment Protection and Biodiversity Act 1999 (EPBC Act), which provides a legal framework to protect and manage nationally and internationally important flora, fauna, ecological communities and heritage places. We submitted our EPBC Act Referral to the Australian Government in November 2024.
The Australian Government will use the information in our Referral and other scientific information to determine whether the project needs assessment and approval under the EPBC Act. Depending on the result, this may be the first step in the Australian Government’s EPBC Act assessment of this project. The outcome of this decision will be made public through the EPBC Act Public Portal: https://epbcpublicportal.environment.gov.au/all-referrals/
We also need to get approval from both houses of the Tasmanian Parliament to reclaim a small part of the Pitt Water Nature Reserve under the Nature Conservation Act 2002 for the Sorell causeway upgrade.
To progress both Tasmanian and Australian Government environmental assessments, we are having ongoing discussions with the Australian Government (Department of Climate Change, Energy, the Environment and Water) and the Tasmanian Government (Department of Natural Resources and the Environment Tasmania, including Parks and Wildlife Service).
What assessments do you need to do?
Part of our project development involves assessing the ecological and heritage values of the project area.
So far, we have done:
- Natural Values Assessments to identify significant flora, fauna, vegetation communities and weeds which will require management prior to and during the works. This includes separate Natural Values Assessments for the marine and land environments.
- an Historical Heritage Impact Assessment to determine the presence of significant historic heritage values and the likelihood of disturbance.
- an Aboriginal Heritage Assessment to identify the presence of Aboriginal heritage values and the likelihood of disturbance.
- a Significant Impacts Assessment to identify potential impacts to matters of national environmental significance.
Where possible, significant ecological or heritage values will be avoided and impacts minimised through appropriate management strategies. For example, the design for both causeways will minimise impacts to important habitat for Tasmanian live-bearing seastars wherever possible.
What is being done to protect animals in the area?
Careful steps are being taken to minimise the impacts on protected species during construction. Pitt Water, including Orielton Lagoon is a Ramsar listed wetland which provides important habitat for protected species including migratory and resident shorebirds, Tasmanian live-bearing seastars and estuary and marine fish.
The areas around the Midway Point and Sorell Causeways provide important habitat for the seastar which is listed as a threatened species under Australian and Tasmanian environmental legislation.
The design for the Midway Point Causeway minimises impacts to important habitat for the seastar on the northern side of the existing causeway.
We have been working with specialist consultants, the University of Tasmania and the University of Sydney to ensure the seastars are protected using best practice methodologies.
We are working on a range of management measures, including:
- relocation of seastars to temporary homes before construction
- building an embankment to protect seastar habitat during construction
- extension of seastar habitat at Midway Point Causeway
- re-establishment of seastars on the causeways after construction.
We will make sure to minimise any disturbance to the feeding and roosting sites of migratory and resident shore birds during construction, maintain ways for fish to move between areas, and plan for best practice erosion and sediment controls to maintain water quality.
Will the current water flows under the causeways be maintained?
Yes. The existing flows will be maintained and where possible improved between Orielton Lagoon and Pitt Water. The existing flow of water under McGees Bridge and the new (second) bridge on the Midway Point causeway will also be maintained.
Why aren’t the causeways straight?
Both causeways have been designed to minimise environmental impacts, including maintaining prime seastar habitat on the causeway walls, where practical.
The design also needs to join other upgrades and the existing highway. On the Midway Point Causeway, the design includes a new bridge to the northern side of the existing McGees bridge, connecting to the Midway Point Intersection Solution project.
Traffic flow also needs to be maintained on the existing causeway while the new causeway is built.
These constraints mean that curves are needed in the new causeways. These curves have been designed to meet safety requirements and improve traffic efficiency.
How has sea level rise been considered in the design?
The height of the causeways has been designed using the latest predictions of sea level rise over the next 100 years.
How has drainage been considered in the design?
Drainage systems have been incorporated into the design of the causeways and new bridge. Stormwater pollutants such as rubbish and sediment will be trapped and further filtered for finer sediments and nutrients before being discharged to the estuary. Stormwater discharges are proposed to be located away from sensitive areas.
Will I be able to walk or cycle across the new causeways?
We will build a new shared use pathway for walking, wheeling and riding on the northern side of the Midway Point Causeway and on the new (second) McGees Bridge. This will link to the new shared use pathway near the Hobart Airport Interchange, once the Tasman Highway is upgraded between the Airport Interchange and Midway Point Causeway.
The existing pathway on the southern side of McGees Bridge will be maintained for fishing and walking, and will no longer connect to the Midway Point causeway. To make it safer for all users, cyclists, skateboarders and other wheelers will be directed away from this side of the bridge.
We will also build a new shared use pathway on the northern side of the Sorell Causeway.
Will I be able to fish off the new (second) McGees Bridge?
The new shared use pathways on the northern side of both causeways will be accessible for walking, wheeling and riding.
The existing pathway on the southern side of McGees Bridge will be maintained for walking and fishing, with a car park constructed between the two bridges for recreational users.
A continuous off-road path is being constructed from the Airport Interchange to Sorell in stages. As a result, people may fish off the new (second) McGees Bridge but it is expected that over time they will need to share the space with an increasing number of people walking, wheeling and riding along this path.
How has road safety been improved?
We will install flexible safety barriers to separate east and west bound traffic, with concrete safety barriers installed on the outside of the lanes. The shared use path will be separated from vehicle traffic and protected behind a safety barrier.
The causeways will be built higher, which will keep them open for emergency vehicle access, and will also reduce times of poor visibility and wet, slippery surfaces during extreme weather events.
What consultation has happened so far?
Public consultation was completed on the broader South East Traffic Solution and the concept design for upgrading the Midway Point and Sorell Causeways.
We are now sharing the latest designs and project information for the Midway Point and Sorell Causeways upgrade with the wider community, prior to designs being finalised.
These videos below show how the changes to the Midway Point causeway may look, Midway Point-bound from Hobart, and Hobart-bound from Midway Point.
Accessibility
If you would like to find out more information and you have accessibility requirements, please contact the project team on the details below. You can find out more about Transport Services' commitment to accessibility on our website here: https://www.transport.tas.gov.au/accessibility
Contact
If you would like more information about these works, please contact Kristie Giblin on 0488 227 427, or email causewayduplication@stategrowth.tas.gov.au