PRO: Tonsley Rail Extension

[mattblack]

You need to have an plan that also covers Marion Rd and the Southern Expressway. Focusing on the easiest intersection of the proposal doesnt solve a whole lot and also not allowing for transport options to uni and hospital missus a major part of what the plan seeks to achieve, in this case I think you should put forward your alternative (bus lanes or whatever). Why isnt the train-tram option the best solution? I understand about future connectivity, but connectivity to where? Why does a train need 300m of straight track, cant a stop be on a gentle curve? Pretty good overall however, I think you need to justify some of your assumptions.

[ozisnowman]

Maybe DTEI should look at upgrading stations to be able to handle Train-Trams on certain routes ie Tonsley Line between Ascot Park and CITY and
likewise future West Lakes and Port Train-Tram routes.

Is it not possible to extend the platform and have a lower platform for the Train-Tram next to the high platform for Heavy-Rail. Linked by a sloping ramp.

Yes some platforms would get long but is that an issue? And how long is a Train-Tram platform anyway?

[Aidan]

You need to have an plan that also covers Marion Rd and the Southern Expressway.

Why? The plan I was responding to didn't. Isn't it safe to assume conditions will be sufficiently similar to what they're assuming?

Focusing on the easiest intersection of the proposal doesnt solve a whole lot

You may regard it as the easiest, but it's fair do say they didn't!

I focused on the South Road / Flinders Drive intersection not because it was easy but because they'd done it so spectacularly badly. Destruction of over a dozen houses and unnecessary removal of many thousands of cubic metres of soil is extremely expensive, and there's a better way that was obvious to me.

and also not allowing for transport options to uni and hospital missus a major part of what the plan seeks to achieve,

Every objective should be questioned. I explained why running tram-trains to that car park is not actually a good way of serving Flinders University.

in this case I think you should put forward your alternative (bus lanes or whatever).

I think I did. From Page 1:
the location of Flinders University on a steep hill prevents the
terminus from serving much of the university as conveniently as it may appear
to on a map. What?s really needed is a station somewhere in the vicinity and a
circulator service to take people closer to where they want to go. The DTS
report mentions the idea of a monorail. This remains a long term possibility,
but meanwhile buses will suffice. Though the DTS mentioned Adelaide Metro
bus services in the area last year, it failed to mention the Flinders University
Loop Bus. This free service currently connects FMC with all parts of the
Flinders University campus. If it were extended to a station in Laffers triangle
and timetabled to connect with the trains, it would provide a better service to
much of Flinders University than tram-trains ever could.

Perhaps I should have added that as so many of the South Road bus services to the City currently bypass FMC, the case for directly serving the hospital looks weak even before you consider how little of the demand to go there is from the City.

Why isnt the train-tram option the best solution?

Expensive vehicles with low capacity and low top speed, not even going where the passengers want.

I understand about future connectivity, but connectivity to where?

I'm not quite sure of the context you mean. If you're referring to extending the railway South, it would probably be Darlington (above Seacombe Road), Trott Park (N of Lander Road) and Reynella (possibly a station near the start of Panalatinga Road, and definitely one at the main bus interchange at the S end of Old South Road). Beyond there it could be extended further to Hackham via the old Willunga Line route.

Why does a train need 300m of straight track, cant a stop be on a gentle curve?

It can, but a station on a curve can't be wheelchair accessible without a ramp.

Pretty good overall however, I think you need to justify some of your assumptions.

I made it clear that I could be contacted by email if anything needed explaining.

[fabricator]

Focusing on the easiest intersection of the proposal doesnt solve a whole lot

You may regard it as the easiest, but it's fair do say they didn't!

I focused on the South Road / Flinders Drive intersection not because it was easy but because they'd done it so spectacularly badly. Destruction of over a dozen houses and unnecessary removal of many thousands of cubic metres of soil is extremely expensive, and there's a better way that was obvious to me.

I couldn't agree more, actually they also demolished the local shops on the South Road/Flinders Drive intersection as well.

The road network in this area is already complicated to drive in, what they have planned makes it far worse. Its really going to do people's heads in trying to drive/walk around in this gigantic mess of a road network. Too many intersections to close together, and no attempt to simplify things, it is an accident (or 50) waiting to happen.

[Aidan]

Focusing on the easiest intersection of the proposal doesnt solve a whole lot

You may regard it as the easiest, but it's fair do say they didn't!

I focused on the South Road / Flinders Drive intersection not because it was easy but because they'd done it so spectacularly badly. Destruction of over a dozen houses and unnecessary removal of many thousands of cubic metres of soil is extremely expensive, and there's a better way that was obvious to me.

I couldn't agree more, actually they also demolished the local shops on the South Road/Flinders Drive intersection as well.

Correct, but so does my plan. It's not actually a particularly good place for shops, and the opportunity to align the Flinders Drive / South Road connection with University Hall Access Road seemed too good to pass up.

The road network in this area is already complicated to drive in, what they have planned makes it far worse. Its really going to do people's heads in trying to drive/walk around in this gigantic mess of a road network. Too many intersections to close together, and no attempt to simplify things, it is an accident (or 50) waiting to happen.

Yes, it's a bit worrying how they fail to recognise that ending lanes in the middle of nowhere is generally a bad idea.

[drwaddles]

Yes, it's a bit worrying how they fail to recognise that ending lanes in the middle of nowhere is generally a bad idea.

Where?

[Aidan]

Yes, it's a bit worrying how they fail to recognise that ending lanes in the middle of nowhere is generally a bad idea.

Where?

In the trenched section of South Road, Figure 7.1 (p56) shows one northbound lane ending before Flinders Drive and another ending below Sturt Road.

IMO a similar mistake was made with the South Road Superway, narrowing it to three lanes instead of four N of Grand Junction Road - but the Superway designers assured me it would be wide enough to easily change it to four lanes if there's sufficient demand.

[Isiskii]

The tram-trains will not be happening.

[drwaddles]

In the trenched section of South Road, Figure 7.1 (p56) shows one northbound lane ending before Flinders Drive and another ending below Sturt Road.

This is not the 'middle of nowhere', it is the merge from the Darlington interchange. 5 lanes down to 3 has to happen somewhow and it is better to space out the merges rather than have them happen all at once.

[Aidan]

In the trenched section of South Road, Figure 7.1 (p56) shows one northbound lane ending before Flinders Drive and another ending below Sturt Road.

This is not the 'middle of nowhere', it is the merge from the Darlington interchange. 5 lanes down to 3 has to happen somewhow and it is better to space out the merges rather than have them happen all at once.

Being downstream of the Darlington Interchange doesn't stop it being in the middle of nowhere. 5 lanes down to 3 does not have to happen anyhow, because there's no good reason to start with 5.

My alternative is to have 2 lanes from the Southern Expressway and 1 from Main South Road going into the underpass, with the rest of the traffic going to the surface lanes to Bedford Park and the Sturt Road intersection. Any other Main South Road traffic that wants to get in would have an opportunity to do so at least until Flinders Drive, but importantly it wouldn't be forced to merge - everyone would have the option of staying in the lane they're in.

[koalaboy]

I have been following these forums for quite a while and have been reading this discussion with great interest. I have to agree with poster mattblack about Aidan's plan. The government's eventual plan is to make South Rd a freeway, so intersections cannot be treated individually. Treatments at one intersection may create issues at the next. Usually, intersections closer than 2-4km spacings need to be considered together. I would be very interested to see how the Southern Expressway interchange fits into all of this without creating a bunch of weaving.

It's not actually a particularly good place for shops

I found it amusing that the intersection of Flinders Drive and South Rd was “not a good place” for a business, but South Rd (eventually to become a freeway) is apparently a great spot for residential houses to remain.

The Sturt Rd underpass cannot be built without diverting traffic around the underpass while maintaining 65,000 vehicles per day. This is where I think Aidan’s plan will start hitting properties. I have also noticed that Aidan's proposal will not allow Flinders Dr traffic to head north unless they use Laffer Rd, not to mention the impossible and dangerous steep ramps from the Flinders overpass down to a roundabout on Laffer Rd. If real design curves were applied to the scheme, all of the vacant land on the Sturt triangle would be taken up by the spiral ramp and bridge ramp.

I think the government’s plan seems extreme, but I don't know how much allowance they are making for the future. The ER predicts South Rd will go up to 100,000 vehicles per day by 2031, from the current 65,000 so that explains some of the increase in size. I actually think 4 lanes are required now to get all the traffic through the underpass. The video does show a wide median down the middle as well, so this is probably like the Gallipoli underpass where they have a big median and breakdown lane to allow for extra lanes in the future.

[drwaddles]

In the trenched section of South Road, Figure 7.1 (p56) shows one northbound lane ending before Flinders Drive and another ending below Sturt Road.

This is not the 'middle of nowhere', it is the merge from the Darlington interchange. 5 lanes down to 3 has to happen somewhow and it is better to space out the merges rather than have them happen all at once.

Being downstream of the Darlington Interchange doesn't stop it being in the middle of nowhere. 5 lanes down to 3 does not have to happen anyhow, because there's no good reason to start with 5.

My alternative is to have 2 lanes from the Southern Expressway and 1 from Main South Road going into the underpass, with the rest of the traffic going to the surface lanes to Bedford Park and the Sturt Road intersection. Any other Main South Road traffic that wants to get in would have an opportunity to do so at least until Flinders Drive, but importantly it wouldn't be forced to merge - everyone would have the option of staying in the lane they're in.

In short:

- If you only have 1 lane entering from Main South Road and 2 lanes from the Southern Expressway then the merge has to occur before this traffic reaches South Road. That is, you are just relocating the same 'problem' further back.

- If the traffic is light enough not to have a problem with a merge further back, then there will be no merge problem at the proposed merge.

i.e. it's a non issue and actually good design practice. You will see this is used in plenty of other high-volume merge locations.

Some examples:

Bad practice - merge to 1 lane before entering freeway. Lots of traffic banked back on the Farmer Freeway during peak because of this

Good merge - never a problem

[koalaboy]

That's right DrWaddles, South Rd has 4 lanes now and the Southern Expressway has 2, which is 6 in total. I only count 5 lanes heading north past Flinders Dr, so one of them has vanished. Also, if you assume that some people from the expressway don't want to go under Sturt Rd, that makes 7 lanes. Once you install an interchange at the Southern Expressway - South Rd intersection, this only becomes worse. It's very easy to focus on one site and ignore issues outside the area of your focus, but in reality the people driving through Darlington don't amazingly appear in the correct lane just south of the Flinders Dr intersection.

[Aidan]

I have been following these forums for quite a while and have been reading this discussion with great interest. I have to agree with poster mattblack about Aidan's plan. The government's eventual plan is to make South Rd a freeway, so intersections cannot be treated individually. Treatments at one intersection may create issues at the next. Usually, intersections closer than 2-4km spacings need to be considered together. I would be very interested to see how the Southern Expressway interchange fits into all of this without creating a bunch of weaving.

The government's plan is to make South Road a non stop corridor, not a full freeway as you seem to envisage. Anyway, the whole Bedford Park area does need looking at together, and both the DTS and I did. But considering combined effects is no excuse for assuming two adjacent junctions should be treated the same way.

It's not actually a particularly good place for shops

You misattributed that quote - I said it.

I found it amusing that the intersection of Flinders Drive and South Rd was “not a good place” for a business,

Except that I didn't say that at all. I said it wasn't a particularly good place for shops. Though not a bad place either, it's nowhere near as good a business location as near the interchange in Laffer's Triangle. There's no good reason to keep the businesses in their current location.

but South Rd (eventually to become a freeway) is apparently a great spot for residential houses to remain.

A slip road separated from the main part of South Road by a landscaped strip. If necessary it could be widened and noisewalls constructed.

The Sturt Rd underpass cannot be built without diverting traffic around the underpass while maintaining 65,000 vehicles per day. This is where I think Aidan’s plan will start hitting properties.

North of Sturt Road I did not suggest any changes, so from Sturt Road to Mimosa Terrace my plan would be just as destructive as theirs. It's not that I couldn't think of other ways to do it, it's just that cost and disruption issues favour their way of doing that bit.

I have also noticed that Aidan's proposal will not allow Flinders Dr traffic to head north unless they use Laffer Rd

Or University Drive.

not to mention the impossible and dangerous steep ramps from the Flinders overpass down to a roundabout on Laffer Rd.

Impossible??? There are plenty of steeper hills than that in the suburbs! Nor is it the only roundabout at the bottom of a steep hill.

If real design curves were applied to the scheme, all of the vacant land on the Sturt triangle would be taken up by the spiral ramp and bridge ramp.

All of it??? Struth, how shallow do you think gradient and curvature have to be for a road with a 50km/h speed limit?

I think the government’s plan seems extreme, but I don't know how much allowance they are making for the future. The ER predicts South Rd will go up to 100,000 vehicles per day by 2031, from the current 65,000 so that explains some of the increase in size.

That figure is based on inadequate public transport, which is one of the things I took exception to.

I actually think 4 lanes are required now to get all the traffic through the underpass. The video does show a wide median down the middle as well, so this is probably like the Gallipoli underpass where they have a big median and breakdown lane to allow for extra lanes in the future.

Which is stupid, because it will never be worth constructing extra lanes in the Gallipoli Underpass.

[koalaboy]

Apologies Aidan for misquoting Fabricator, I am still learning how to use these forums. Based on your reply I can see that you never get anything wrong or make a mistake in life.

By definition a freeway is a road that is free flowing, or as the government says non-stop. They don't need to be 100km/h, but they need to follow the same principles such as no direct access to the freeway apart from interchanges. I never said that adjacent intersections needed to be treated the same way, just considered together. There is a big difference. This simply means that your need to draw up a full scheme from end to end, when intersections are closely spaced. Looking a one section in isolation is pointless.

A slip road separated from the main part of South Road by a landscaped strip. If necessary it could be widened and noisewalls constructed.

Widened where? Into their front gardens, by acquiring their land? Not to mention being on the north side of their block, a high noise wall would cast a shadow over their entire front yard. Acquiring a proportion will cost nearly as much as buying the whole block. And suddenly your footprint is becoming no different.

Or University Drive.

Have you not seen University Dr in the peak hours? It can’t handle much more traffic, if any at all. Pushing the problem somewhere else and ignoring the impact seems to be your solution for everything. Once again, the solution needs to be looked at in its entirety, not one section in isolation.

Impossible??? There are plenty of steeper hills than that in the suburbs! Nor is it the only roundabout at the bottom of a steep hill.

Obviously Aidan you are not aware of these annoying things called design standards and guidelines. Unfortunately, to avoid litigation most professionals have to follow them. Over time standards change to reflect higher standards of safety. In some instances due to the steepness of the existing terrain, there is no other option but to install a sub-standard slope or intersection. But given the terrain in Darlington, your scheme would never be allowed. Even if the grades you suggest were possible, the overpass would not meet the disability act requirements. How would pedestrians cross South Rd at Flinders Dr on your 30% grade bridge?

All of it??? Struth, how shallow do you think gradient and curvature have to be for a road with a 50km/h speed limit?

Yes, all of it. Your spiral is also about 1/3 the minimum radius required, especially coming off an 80km/h design road. You can’t transition design speeds instantaneously from 80 to 50km/h. Maximum grades for 50km/h are about 10% for short sections, but not on approaches to intersections because rear-end crashes will become far more common. You also need sight distance over crests and around corners, all of which will make your scheme bigger. Your overpass will be lucky to come down to ground level before Sturt Rd, Laffer is impossible.

That figure is based on inadequate public transport, which is one of the things I took exception to.

And you would know this how? Politicians win votes more quickly and easily with road projects, about 90% of us drive. Everyone knows PT is the better long-term spend and is more sustainable, but as long as politicians dictate what is built, they will go for the more-popular road projects (for example Southern Exy Duplication). Near doubling of the population in the next 30 years and the existing low-density housing down south will result in growth of traffic. Unless they made PT free, people will still love to drive, particularly with a free-flow road. It’s called induced demand. If the road wasn’t free-flowing and left to clog up, yes people would try PT, but if it is quicker door to door by car, people will continue to drive in big numbers. Look at major cities with good PT, they still have massive traffic chaos.

Which is stupid, because it will never be worth constructing extra lanes in the Gallipoli Underpass.

They don’t need to “construct” them, they are already there. It will cost peanuts to convert. Just take out the median, bike lane and parking lane and you have one more lane without changing the bridge or walls. Not stupid at all, it’s called future-proofing. Luckily some people plan for the growth, instead of basing everything on present day for all of their decisions.