Raglan Avenue / South Road

[marquisite]

I've been watching this thread for a long time now.. I see a few years ago there was discussion of deviating Raglan Avenue near Castle Plaza to Ackland Street thus eliminating one set of traffic lights - unfortunately the picture posted by ReallyBad doesn't show anymore so I hope my vision hasn't stolen too much of the spotlight.

I'm not sure what is destined for the empty lots to the north of Castle Plaza.. maybe bulky goods? (Bonus points if anyone can work out where in Adelaide the two buildings come from.) Oh, and while I'm at it, why not sink the railway line thus eliminating one level crossing?

PS: I haven't costed anything (even if I did the Government's costing would be much MUCH higher), and I'm no expert, but I still have visions even if they aren't that great

Anyway, here goes... my vision does not fully close off Raglan Avenue - similiar to the Parafield Airport roads around the retail area, it will be converted to in-only for northbound traffic. All other traffic would need to use the diverted connector road intersection for South Road access (Ackland Street / Edward Street). Also, maybe a Roundabout isn't the way to go for Raglan Avenue - trafflic lights might be needed depending on the volume of traffic.



Edit 1: Appended two minor changes as per Aidan's feedback; Edit 2: Added bridge over South Road

[Aidan]

I've been watching this thread for a long time now.. I see a few years ago there was discussion of deviating Raglan Avenue near Castle Plaza to Ackland Street thus eliminating one set of traffic lights - unfortunately the picture posted by ReallyBad doesn't show anymore so I hope my vision hasn't stolen too much of the spotlight.

I'm not sure what is destined for the empty lots to the north of Castle Plaza.. maybe bulky goods? (Bonus points if anyone can work out where in Adelaide the two buildings come from.) Oh, and while I'm at it, why not sink the railway line thus eliminating one level crossing?

PS: I haven't costed anything (even if I did the Government's costing would be much MUCH higher), and I'm no expert, but I still have visions even if they aren't that great

Anyway, here goes... my vision does not fully close off Raglan Avenue - similiar to the Parafield Airport roads around the retail area, it will be converted to in-only for northbound traffic. All other traffic would need to use the diverted connector road intersection for South Road access (Ackland Street / Eastland Street). Also, maybe a Roundabout isn't the way to go for Raglan Avenue - trafflic lights might be needed depending on the volume of traffic.

Looking at the offscreen part of your picture, you seem to have completely overlooked the main objective: to eliminate the traffic lights on South Road. The road you call South Road - Raglan Avenue Connector should be named Edward Street and should bridge South Road rather than joining it. And there's no good reason to deny traffic the opportunity to turn left into South Road from Raglan Avenue - it's only right turns that are a problem.

A roundabout will be suitable as long as it's designed to accommodate large trucks.

Lowering the railway would be a lot more expensive than raising Raglan Avenue, but thats not the reason it shouldn't be done. The reason it shouldn't be done is disruption - closing Raglan Avenue for a few months is tolerable, but the trains must keep running!

[Nort]

Lowering the railway would be a lot more expensive than raising Raglan Avenue, but thats not the reason it shouldn't be done. The reason it shouldn't be done is disruption - closing Raglan Avenue for a few months is tolerable, but the trains must keep running!

Has this section of line been upgraded yet?

I think that in a few years time the current upgrades will be seen as a missed opportunity to upgrade various crossings without introducing much extra disruption.

[marquisite]

Whilst I don't disagree that a road bridge could be cheaper and less disruptive, I agree with Nort that now is a great time to upgrade some of the intersections with grade separation...

And without trailing too far off topic, this was just one of the ideas I had for the Raglan crossing whilst I was tackling the signalised intersection of South Road.

Aidan: Any visuals regarding bridges over the railway and South Rd to better grasp your views? (I've modified the image I posted to include the correct road name and the addition of a left turn option for accessing South Road (northbound)

[Aidan]

Lowering the railway would be a lot more expensive than raising Raglan Avenue, but thats not the reason it shouldn't be done. The reason it shouldn't be done is disruption - closing Raglan Avenue for a few months is tolerable, but the trains must keep running!

Has this section of line been upgraded yet?

No. But even when it does close for upgrading, the objective should be to reopen it as quickly as possible.

I think that in a few years time the current upgrades will be seen as a missed opportunity to upgrade various crossings without introducing much extra disruption.

Upgrading crossings is one thing. Lowering the trackbed by a few metres is quite another!

No crossing on the Noarlunga Line needs to be replaced by a bridge requiring significant lowering of the railway - with the arguable (but technically very difficult) exception of the Emerson crossing.

More importantly, the crossings most in need of grade separation could be done so while keeping the railway open.

[Aidan]

Aidan: Any visuals regarding bridges over the railway and South Rd to better grasp your views? (I've modified the image I posted to include the correct road name and the addition of a left turn option for accessing South Road (northbound)

OK. Just a rough one, bridges are in purple.

[Omicron]

I have a sneaking suspicion that ensuring a reasonable, manageable slope on these bridges and allowing sufficient clearance to South Road would require much greater length than is being shown. Look at the size of the tram overpasses and the Cross Road overpass - I don't know if many places along South Road allow the luxury of space on both sides to allow for bridges of such size.

[Aidan]

I have a sneaking suspicion that ensuring a reasonable, manageable slope on these bridges and allowing sufficient clearance to South Road would require much greater length than is being shown. Look at the size of the tram overpasses and the Cross Road overpass - I don't know if many places along South Road allow the luxury of space on both sides to allow for bridges of such size.

The bridges on South Road are designed for trucks to be able to stay at 60km/h as they go over them. A bridge across South Road would have a 50km/h speed limit, and much less traffic so it wouldn't really matter if trucks slowed down a bit on their way over. Therefore steeper gradients are appropriate.

Would the bridges have to be longer than the lines on my map? I wouldn't be at all surprised - for one thing, there are vertical curvature issues to consider.

Does that worry me? No, when I posted the map I said it was only a rough one. And there's plenty of space to make the bridge longer.