11 June 2024

Light rail update: Short tunnel proposed to negotiate tight State Circle bend

| Ian Bushnell
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light rail render

The proposed light rail stop on State Circle at Kings Avenue. Image: ACT Government.

A short tunnel under Commonwealth Avenue to State Circle East has been proposed as the solution to the engineering problems posed by this tight bend on the preferred light rail alignment to Woden.

In a project update, Major Projects Canberra also laid out tree planting plans on Commonwealth Avenue, confirming that the median cedars would be removed under the preferred route.

The update provided some of the most detailed plans yet for the Stage 2B leg to Woden as part of its work on compiling the draft Environmental Impact Statement it expects to complete by the end of the year.

For now, the alternative Barton alignment, despite being acknowledged as more complex and costly, remains on the table as a backup if the State Circle issues on the preferred route are insurmountable.

The tunnel, known as a cut and cover, would mean the tracks on the Commonwealth Avenue median would descend on the approach to Parliament, going under Commonwealth Avenue and popping out on the State Circle median.

The project team says this solution should sit quite lightly in the landscape and be simple from a finished product point of view.

However, it will still be quite complex to construct in a way that doesn’t unnecessarily impact the surrounding traffic.

The alignment would then run around State Circle on the median until nearing Adelaide Avenue where it is proposed to cut through the woodlands over Capital Circle and then via a new bridge over State Circle to continue down the median of Adelaide Avenue.

However, the project team is also considering a verge alignment inside State Circle from Sydney Avenue.

It believes that this approach to the State Circle challenge is an appropriate solution to address the traffic, heritage and multiple approvals issues confronting the project.

Also revealed was that the 45-metre long light rail stops on State Circle will have to be curved to maintain the character of the parliamentary area and not turn the “20 cent coin” that is Capital Hill into a 50 cent piece with edges.

The team is conscious that the project needs to win the approval of Parliament, and it only wants to do it once.

tree-planting plan

An illustration showing the tree planting scheme for Commonwealth Avenue. Photo: ACT Government.

The Commonwealth Avenue Light Rail Master Plan proposes planting a row of pin oaks between the tracks north and south of the lake, flanked by Himalayan cedars and Chinese elms.

The teams say tree aging and disease have eroded the value of the avenue somewhat, and the new planting scheme is designed to restore a stateliness to the corridor.

No trees would be planted on the median between City Hill and Parkes Way to retain the view.

If the Barton alignment got the nod, trees along National Circuit that were also aging and diseased would also need to be removed.

A decision has not yet been made on the plantings for Adelaide Avenue.

The update reiterates that the lake crossing will be a new bridge between the current spans of Commonwealth Avenue Bridge to create a new prioritised corridor that would move up to 2500 people an hour, compared with the current estimate of 1100 an hour per road lane.

This would be an increase in capacity that was not necessarily subject to congestion and delays associated with travelling on the road.

While buses could be given priority around State Circle from Adelaide Avenue, that would require creating a new transit lane.

Major Projects Canberra was looking at completing the draft EIS by the end of this year, followed by an extended period for public exhibition and submissions.

After submissions are assessed and digested, the EIS is expected to be finalised by the middle of 2025 and submitted to the ACT and Commonwealth for approval.

The project team will then move on to detailed design and the planning approvals – parliamentary, ACT and Commonwealth (NCA).

A Works Approval is not expected until at least late 2026 or early 2027.

Some early works that do not need approval could commence before an official construction start.

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The project team has divided the Stage 2B route into precincts: the Commonwealth Avenue Precinct from the end of Stage 2A to Parliament; Parliament House Precinct; the Inner South Precinct, which is largely Adelaide Avenue and Yarra Glen; and the Woden Precinct.

This will allow it to identify local issues and should make it easier for people to provide feedback.

Precinct plans showing proposed works, the Light Rail Commonwealth Avenue Masterplan, Commonwealth Avenue Landscape Heritage Advice, Commonwealth Avenue Bridge Heritage Assessment, and the Commonwealth Avenue Landscape Structure Plan will all be available on the YourSay site.

The consultation to inform the draft EIS closes on 30 June.

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Just what part of the Plan that took so long to develop is this “patch” needed to cover up?

Keyboard Warrior8:45 pm 09 Jun 24

A short tunnel… I will assume this won’t add time or cost to this well developed Labor ego-eco project.

Andrew Clarke2:20 pm 09 Jun 24

Why are we spending billions of dollars to replace the number 4 bus with a tram? It doesn’t need more engineering work and it will take you all the way to Belconnen with no fuss at all.

No fuss? But quite unreliable. To rely on a connection I routinely need to catch an R4 two times earlier than the one that should connect. Unreliability emphasised by up to 3 R4s from Belconnen scheduled at 6 minute intervals sometimes appearing at Woden one behind the other.

The number 4 bus is being replaced by a city wide infrastructure that increases connectivity across and between towns, in ways that are attractive to people and which cuts down on car and bus congestion, and is better for the environment. Win-win-win-win. Four wins, not number 4 bus.

It’s interesting to see that after all this time and the enormous amounts of money spent they still haven’t figured out an effective way of getting their tram from Commonwealth Ave onto Adelaide Ave.
I wonder if they have even thought about the difficulties they are going to face going along Adelaide Ave on the way to Woden. There has been no mention of any of this so most likely they are still completely ignorant of the problems they will face.

The light rail should go from Commonwealth Park across to Kings Avenue and then down Kings Avenue to State Circle. This has many benefits – shorter bridge span required to get across the lake, captures employees in Govt departments in Barton giving instant patronage, barely touches State Circle to get onto Adelaide Avenue therefore no need for extra expense such as a tunnel, and finally you have the line available and ready to fork off for the proposed extension towards Kingston & the Airport. It’s a no brainer!

GrumpyGrandpa6:40 pm 08 Jun 24

In my opinion, 2a shouldn’t have proceeded until the technical difficulties of 2b were worked out, route determination and costings made.

As it is now, the government has spent a significant amount of our money on a train to nowhere.

The government has also been pouring our money into a new transport hub at Woden, in anticipation of 2b.

My real concern is that it appears that 2b will be built for ideological reasons, regardless of the cost and the route taken.

Should the main focus of public transport be to move people from A to B quickly?

Personally, I’d rather travel on a train, than a bus but from everything I’ve read and heard, travelling via LR is the slowest option.

You hit the nail on the head Grumpy.

“… travelling via LR is the slowest option”
From what I’ve heard, being a ‘southerner’ I don’t have actual experience, the LR trip from Gunghalin to Civic is appreciably quicker – and it’s not only due to the dedicated track and traffic light priority.

Nevertheless, I think most Canberrans, south of the lake, are of the opinion that the LR trip from Woden to Civic will be slower than the current bus ride.

Otherwise with respect to the rest of your post, I agree with Harry in that you “hitn the nail on the head”.

If they wanted to build a whole network the best route to start with would have had an outstanding business case. However it wasn’t. The first leg was sketchy and we have to wait for time to catch up for the rest of time. Given we don’t want to wait, we’re forcing though ‘solutions’ and trying to create the problems they are due to solve.

A fast speed ring rail would would, however requirments something not on display which is intelligence and forward planning.

GrumpyGrandpa9:57 pm 09 Jun 24

Hello JustSaying,
While I live southside, I’ve travelled on LR Gunners to the City, a few times.
The apparent advantage LR has for that trip is the reduced number of LR stops (as opposed to previous bus stops) , the speed of loading, as the passengers have already tagging-on prior to boarding, peak-hour road congestion, dodging push-bikes and traffic light sequencing.
The advantages LR Gunners to the City has over buses don’t exist City to Woden, in particular with Adelaide Ave being an 80kph road with no bus stops, traffic lights etc. It’s proposed to add a number of LR stops along Adelaide Ave which will further increase the travel time for those travelling from Woden or beyond.

As I said: “… most Canberrans, south of the lake, are of the opinion that the LR trip from Woden to Civic will be slower than the current bus ride.”

Another case of this useless gumment pi**ing our money down the drain. We’re already in massive debt and had our credit rating reduced. I’m.sick.of these clowns.

Julie Lindner3:29 pm 08 Jun 24

If you insist on last century’s infrastructure it should all be underground like the smart capital cities have done. Leave the above ground to cars and buses.

If you put different tyre-clad bogies on the battery-driven trams…would solve a whole lot of issues. Oh, but then you couldn’t call it light rail, you would have to acknowledge that Labor is driving the ACT down a very expensive rabbit hole further desecrating Canberra as a capital city. Why not just tunnel right under Parliament House? It will be known as the Labor Deep Hole of Capital ($).

Now if Liberal (ACT) could find a convincing leader with an alternative transport plan, there is some hope for the tax-burdened citizens of Canberra.

Isn’t it amazing…. when the goverment (a Green’s one at that) wants to remove numerous trees they are suddenly determined to be “old” and “diseased” but when an individual wants to remove an actually dead tree, then suddenly it needs to stay for bird and animal habitat

It certainly depends on what you are trying to achieve. Old trees often shed branches, it is part of their continuing. Ancient oak trees in Europe, including UK, go ‘stag-headed’. This is every 150 years or so. Leave the heritage ceders. Reject argument that they are over-mature, forester talk for needs to be cut down.

Seriously! Now a new tunnel and a new bridge!! Costs spiralling no doubt. How about an electric bus in a bus lane. Cost – paint to create bus lane!

Buses coming off Adelaide Avenue to go around State Circle?

For the price we could get a TBM and install high speed train underground from one end of Canberra to the other.

It would be great if the local council could just focus of fixing and maintaining the roads.

Why the hell is this still being worked out? Absolute clown show.

HiddenDragon7:47 pm 07 Jun 24

Eleven months on, the Stage 2B circus lurches ever closer to my modest proposal –


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