The weird things about Adelaide CBD road

[Waewick]

I was looking at a map of the Adelaide CBD when thinking about ways to fix Glen Osmond Road, and a few things occured to me which I find very strange

Wakefield Street and King William Street are the only two roads which provide a major thoroughfare through the city. Both are wide roads from both sides.

However King William Road ultimately ends at a dead end in Mavlern.

Jeffcott/Morphett Street, which turns into Sir Lewis Cohen, hits a dead end at Greenhill Road

Glen Osmond Road, Or state highway 1 end at a dead end South Terrace and sort of dog legs to Pultney.

Pultney Street, which is supplied by 2 very busy roads being Glen Osmond and Unley Road hits a dead end at North Terrace (this is thanks to Uni of Adelaide I believe)

South Terrace is just hopeless and can hardly be considered useful in this debate.

Hutt St/East Terrace hits a dead end North Terrace and dies into a small local road called George Street.

Currie/Grenfell which is fed by Henley also ends as a dead end.

The only other road which provides some semblance of continuity is West Terrace, which is fed by Port Road, and Goodwood road and it's extremities and provides access to ANZAC highway and the other roads flowing through.

My theory is that these weird roads are contributing to the traffic issues we have upstream.

is there an opportunity to fix some of these issues and improve traffic flow further upstream

[Maximus]

Mate, I think you're spot on. I suppose we all inherently know this information, but rarely do we think about it in such a deliberate way, as you have done. Certainly, for a 'planned city', the roads don't seem very well planned when you list it like this! There are most likely very good reasons (or at least they seemed like it at the time) for everything you've listed, but it's probably more helpful to think about what can be done in the future, rather than what has been done in the past.

For mine, until there's a viable alternative, Wakefield/Grote needs to be kept wide and encouraged as the major thoroughfare. As we've discussed elsewhere, the notional CBD 'ring route' provides a reasonably viable passage when attempting to traverse the CBD north-south, but it's not so practical in the east-west direction. This is why I believe Wakefield/Grote should be kept as a 3-lane road, with an underpass through Victoria Square.

As for the rest of it, I'm not sure. One initial thought: assuming the old RAH is torn down, could Frome Road be re-aligned so that it meets with Hutt St at North Tce?

[Waewick]

I agree.

I actually think considering turning some of the streets in to 1 way streets would help. For instance Pultney goes one way and morphett the other, you can then fix the alignment of other roads to suit.

My original thought was to improve the passage of roadusers down Wakefield and create a series of arc from that - the big problem is Clipsal and the Britannia round about...

[crawf]

You do raise a good point Waewick.

If there is any road I would like to see changed, it's Rundle Road. Instead of branching of Rundle Street, it should instead branch of the busier Grenfell Street and connect with the existing Rundle Street in Kent Town. This would go straight through the existing Rymill Park, though it will open up the opportunity to make Rundle Park much bigger including the very popular The Garden of Unearthly Delights.

Rundle Road as it is, is very wide and doesn't carry that much traffic compared to other roads. Ofcourse if this did happen, Rundle Road and Rundle Street in Kent Town would have to undergo a name change.

Just a thought.

As for the rest of it, I'm not sure. One initial thought: assuming the old RAH is torn down, could Frome Road be re-aligned so that it meets with Hutt St at North Tce?

That would encourage more traffic in the area and destroy the golden opportunity of transforming the old RAH site into something that could benefit the entire state. Eg tourism, educational, accommodation etc.

[Waewick]

I think they really need to look at the interaction of the major roads

if you have a look, glen osmond rd crosses, Cross Roads, Fullarton and Green Hill Roads before terminating basically at Pultney.

that is 4 major arterial routes crossed by another one - surely that can't be sustainable moving forward (induced demand or not)

Personally, without a degree in civil engineering, I think they to focus on Glen Osmond Road as it hits Green hill road OR Fullarton.

My favorite concept is diverting the traffic down fullarton and creating an underpass under Greenhill - largely because there is room on the Glenside Campus side of the road and that is a frustrating problem - however this will just lead to a bottle neck at the Britannia Round about.

But I think that could be solved by removing the fullarton road extension and making it a more traditional junction.

Alternatively, Glen Osmond Road needs to be re-aligned to Hutt Street, with the George Street extension to become the off shoot road - but can Hutt Street deal with the demand?

All I can say is they have made a fair old mess of the Grid

[Aidan]

I was looking at a map of the Adelaide CBD when thinking about ways to fix Glen Osmond Road, and a few things occured to me which I find very strange

Wakefield Street and King William Street are the only two roads which provide a major thoroughfare through the city. Both are wide roads from both sides.

Yet they stopped at the terraces in Colonel Light's original plan!

However King William Road ultimately ends at a dead end in Mavlern.

I wouldn't count T junctions as dead ends.

Jeffcott/Morphett Street, which turns into Sir Lewis Cohen, hits a dead end at Greenhill Road

It was once planned to align it with Goodwood Road, but doing so wouldn't offer any great advantage over the current situation.

Glen Osmond Road, Or state highway 1 end at a dead end South Terrace and sort of dog legs to Pultney.

Frome Street, which didn't feature in Light's original plan at all, was once planned to link up with Glen Osmond Road.

Pultney Street, which is supplied by 2 very busy roads being Glen Osmond and Unley Road hits a dead end at North Terrace (this is thanks to Uni of Adelaide I believe)

I also believe so.

South Terrace is just hopeless and can hardly be considered useful in this debate.

Why?

Hutt St/East Terrace hits a dead end North Terrace and dies into a small local road called George Street.

There was a plan to extend it across East Terrace and through the Parklands (to Main North Road, I think, though I could be getting it mixed up with the Frome Road plan).

Currie/Grenfell which is fed by Henley also ends as a dead end.

What you regard as dead is very much alive! It doesn't do too badly directing traffic to Rundle and Bartels (though of course this doesn't mean there's no room for improvement).

The only other road which provides some semblance of continuity is West Terrace, which is fed by Port Road, and Goodwood road and it's extremities and provides access to ANZAC highway and the other roads flowing through.

My theory is that these weird roads are contributing to the traffic issues we have upstream.

is there an opportunity to fix some of these issues and improve traffic flow further upstream

Very limited opportunity, as they're only minor contributors. The main cause of the traffic issues is the number of people driving into the City, and the best way to fix that is with public transport improvements. Realigning City roads is so far down the list of priorities that it probably wouldn't be worth bothering with even if it wasn't so controversial!

[claybro]

I thought we were trying to keep cars out of the CBD.

BUT. I think the FullartonRd/ Dequetteville/Hackney Rd alighnment could do with some major improvements

[Waewick]

yes, but given we rely on buses, congestion makes it even less desirable (why be stuck in traffic in bus when you can be stuck in traffic in your car?) so I do actually agree with your sentiments.

They way I was looking at it was trying to utilise the existing infrastructure to improve congestions for all.

One of my ideas I can't quite figure out is creating a number of one way roads in the CBD and creating a loop system. Basically you would leave King WIlliam and Wakefiled Streets as dual carriage way and create circular loops around the CBD - ultimately everything leads to the ring route around the parklands.


The idea is reduce car congestion which can them improve PT performance.

Another idea was to re-direct Glen Osmond traffic at some point - at minimum making the Glen Osmond extension a bus/bikeway - my original thought was to have Pultney Street as one way leading towards North Terrace, with Hutt Street going the opposition way, but I can't work out how to duplicate that on the western side.

I just think we need to think outside the box, if we improve congestion for cars we can then improve PT by stealth thus making it more attractive.

sorry for the posting style, it is more me putting down what I am thinking rather than a systematic plan.

[claybro]

Another idea was to re-direct Glen Osmond traffic at some point - at minimum making the Glen Osmond extension a bus/bikeway - my original thought was to have Pultney Street as one way leading towards North Terrace, with Hutt Street going the opposition way, but I can't work out how to duplicate that on the western side.

I agree with one way streets Waewick. We could do with some East/West as well. As far the the Western side, West terrace is actually the width of Pultney and Hutt put together, so I guess that is 2x one way streets in one anyway. Agree that that whole Eastern side is a mess, much of it a result to the Brittania Roundabout, and the close spacing of Rundle Road and North Terrace intersections along that Eastern flank. I would like to see an underpass at the roundabout so Fullarton flows into Dequetteville, an underpass at Bartells road, Rundle Road and North terrace, so it becomes a proper inner ring around the CBD.

[Waewick]

I would love an underpass, but I guess I am looking at it without actually having spend money on infrastructure that we don't have.

I was thinking about Glen Osmond Road, a bit (I know this seems like I am harping on a fair bit about this, but it is my thought of the moment)

So if I go through the intersections as you hed into town

Firstly,

Crn Greenhill and Glen Osmond

this is the most normal intersection where you have two lanes going either way and a slip lane to turn left onto Greenhill Rd.

I must add, there is 2 dedicated turning lanes from Greenhill onto Glen Osmond.

Crn Glen Osmond and Hutt

You have four lanes (it turns to three 50 metres after you cross Hutt Street) going straight ahead and 3 going back towards the hills

Strangely, you have 2 turning lanes to turn onto Hutt Street, but only one slip lane to turn left back onto Glen Osmond - so basically this theory is traffic will use it into the city but not out??

Cnr Glen Osmond and Pulteney

This one is especially strange given it is the termination of state highway 1. You have a single turning lane onto Pulteney Street but no dedicated slip lane off pulteney (there is a bike lane people use to turn left but technically this is illegal)

Corner South Terrace and King William Road

I know there is 1 dedicated turning lane onto King William Street, but I'm not sure if there is a dedicated turning lane off King William

Corner of South and Morphett

There is a dedicated turning lane onto South Terrace, but no dedicated turning lane onto morphett.

The road then leads onto ANZAC highway, crossing West Terrace/Goodwood Rd Junction.

So as you can see, there has been some serious confusion as to what Glen Osmond Road actually serves? Clearly the government are aware people want to turn onto Hutt - hence the 2x turning lane - but why then does Hutt still remain directed towards George Street in return?

I know from experience that Pulteney doesn't get a massive amount of left turns, hence the lack of dedicated turning lane.

Now I've written that down, I'm going to bed so I can think about it

oh and Aiden, I call them dead ends because it is a stop in continuity which in my experience seems to cause the congestion in Adelaide. We appear to have sufficient road ways but they seem to be structured in such a manner to cause congestion.

Ideally, why I would like to see, is all roads flowing be it dual carriage way or one way. as I mentioned previously, ideally I'd love to be able to create some one way roads which would provide extra space for dedicated PT and bike lanes without significantly impacting road travel.

I realise the goal is to increase PT, but I'm a realist, if we can improve traffic congestion and PT reliability we are going to start winning the battle because PT won't seem so onerous.

[Aidan]

Crn Glen Osmond and Hutt

You have four lanes (it turns to three 50 metres after you cross Hutt Street) going straight ahead and 3 going back towards the hills

Strangely, you have 2 turning lanes to turn onto Hutt Street, but only one slip lane to turn left back onto Glen Osmond - so basically this theory is traffic will use it into the city but not out??

No, the theory is that turning into Hutt requires hillsbound traffic on Glen Osmond Road to be given a red light, and two lanes almost halve the time that's needed for. Coming out of the City, traffic can turn left when Hutt has the green light, as well as when traffic turning into Hutt has the green light.

Cnr Glen Osmond and Pulteney

This one is especially strange given it is the termination of state highway 1. You have a single turning lane onto Pulteney Street but no dedicated slip lane off pulteney (there is a bike lane people use to turn left but technically this is illegal)

Corner South Terrace and King William Road

I know there is 1 dedicated turning lane onto King William Street, but I'm not sure if there is a dedicated turning lane off King William

There's not, but there are turn lanes to and from Peacock.

oh and Aiden, I call them dead ends because it is a stop in continuity which in my experience seems to cause the congestion in Adelaide. We appear to have sufficient road ways but they seem to be structured in such a manner to cause congestion.

As I said, it may cause a bit of congestion, but insignificant compared to the huge amount of traffic which is the main cause.

Ideally, why I would like to see, is all roads flowing be it dual carriage way or one way. as I mentioned previously, ideally I'd love to be able to create some one way roads which would provide extra space for dedicated PT and bike lanes without significantly impacting road travel.

The one way roads you suggested would cause a lot of inconvenience for little if any benefit.

I realise the goal is to increase PT, but I'm a realist, if we can improve traffic congestion and PT reliability we are going to start winning the battle because PT won't seem so onerous.

The trains have much more potential there.

[Waewick]

I'm curious are you into transport planning or similar? Not trying to be a smart arse but if you are I can change the way I'm posting. Rather than speculating I'll just ask the question

[Aidan]

Yes I am - ask away!

[Maximus]

Yes I am - ask away!

I'll ask: what is the theory as to why one-way streets are beneficial? And why do you say they would result in "little if any benefit"?

There must be at least one good reason why some cities have one-way roads, otherwise it wouldn't ever be done(?!).

[Aidan]

I'll ask: what is the theory as to why one-way streets are beneficial? And why do you say they would result in "little if any benefit"?

There must be at least one good reason why some cities have one-way roads, otherwise it wouldn't ever be done(?!).

There are at least two good reasons why some cities have one way streets. The first is to provide buildings with accessibility or frontage. The second is to increase capacity.

Laneways are the most obvious example of the first reason - providing access without the expense of the extra land needed to make them two way. Alternatively the use of one way streets allows a tighter grid so that no laneways are needed, though I'm not aware of any local examples of that. Portland (Oregon) is quite well known for it, and is said to have been designed with as many street corners as possible after it was noticed that land on corners was worth more.

The second reason is often the result of the roads being too narrow for modern requirements. Diverting traffic onto parallel roads removes bottlenecks. Traffic flows a bit more smoothly when there's more lanes, and there's also a slight advantage with fewer phases at traffic lights.

The N-S roads in the City of Adelaide are far too far apart for this to be practical, and are wide enough for it not to be needed. Making some of the E-W roads one way is more practical (eg. Pirie-Waymouth westbound only, and Franklin-Flinders eastbound only, fitting in well with the way the squares already divert traffic). But the Adelaide City Council currently oppose it. Their main objective at the moment is to make the streets better for pedestrians, and making things better for vehicles doesn't (in their opinion) fit well with that objective.