[U/C] M2 North-South Motorway

[[Shuz]]

Surely they would have put in an on/off ramp in the Castle Plaza vicinity.

[Nort]

Surely they would have put in an on/off ramp in the Castle Plaza vicinity.

Why? The tunnel is being built through that area precisely to avoid having to acquire too much property and doing surface level works, exit/entry points to the tunnel along its length would make the tunnel construction a lot harder and need those surface works.

Plus Castle Plaza isn't that big a destination, most of the traffic going to/from there would be relatively short trips of exactly the type planners don't want to encourage to get on the motorway.

[ChillyPhilly]

I'd like to see a bit more information on this, "Airport Link". What is it? I can't see how this new tunnel/motorway is supposed to "link" with the airport apart from just using the existing roads (Sir Donald Bradman, Richmond and Henley Beach)? Anyone found any more info on it?

I don't think much has been publicly released yet, but based on previous mentions of things it seems like the idea might be for more airport traffic to use Richmond Road.

It would be the idea to construct a new freight-only link from the western end Richmond Road to the airport.

[baytram366]

What happened to the talk of having a tunnel under the airport to link with the current dead end section of Richmond Road? Or was it just that - talk?

[AG]

Be interested to see how competing on-ramp and off-ramp traffic is managed between Anzac Highway and the northern end of the Southern Tunnel. The motorway could end up very congested if south bound on-ramp traffic from Anzac Highway is not separated from off-ramp traffic to Cross Road and South Road southbound, and vice versa.

[aceman]

something doesn't seem right here, northbound once you enter the tunnel at tonsley you can't get off until anzac highway? no option to get off at cross rd which is the biggest road we have that runs east west? wow the anzac highway on/off ramps are going to bank up onto the motorway itself.

[bits]

no option to get off at cross rd which is the biggest road we have that runs east west?

Isn't Grand Junction Road bigger in every way?
Greenhill Road has the biggest volume.
Followed by Regency Road also with more volume than Cross Road.

Cross Road is the 4th biggest east west road.
Although I think Port River Expressway also might challenge that.

[aceman]

no option to get off at cross rd which is the biggest road we have that runs east west?

Isn't Grand Junction Road bigger in every way?
Greenhill Road has the biggest volume.
Followed by Regency Road also with more volume than Cross Road.

Cross Road is the 4th biggest east west road.
Although I think Port River Expressway also might challenge that.

let's break this down further.

grand junction road already has on/off access. the north south corridor doesn't even cross greenhill hill road so that makes it irrelevant. Regency road on/off is currently being worked on and is nearly completed. port river expressway is part of a full blown interchange with no traffic lights.

I was referring to largest road left to cross in the corridor which also connects to the big highway that takes you in and out of adelaide. seems to me that the cross road intersection which also includes a railway level crossing has been placed in the too hard basket so they'll just tunnel under it all and leave everything on the surface untouched.

[Nort]

. the north south corridor doesn't even cross greenhill hill road so that makes it irrelevant.

Not at all, Richmond Road for most practical purposes can be considered an extension of Greenhill Road.

[aceman]

. the north south corridor doesn't even cross greenhill hill road so that makes it irrelevant.

Not at all, Richmond Road for most practical purposes can be considered an extension of Greenhill Road.

spot on. and according to the maps shown there will be on/off at Richmond road.

[bits]

spot on. and according to the maps shown there will be on/off at Richmond road.

So there is huge capacity east west from the north south motorway.

Industry traffic will be sent north towards Truro.
From there they will head to the industrial areas around Wingfield and the second city of Elizabeth.

All the talk is how to move traffic away from the the steep decline that leads to the Portrush/Glen Osmond/Cross intersection.
While you are suggesting to double down on that intersection and making it the preferred path.

Forget about Cross Road, it is a local road.

[aceman]

while there can be opposing arguments as to whether a road is a local road or not the reality is that if there aren't sufficient entry exit points on this corridor it will just lead to congestion at entry exit points. as an example northbound if the only entry exit point between tonsley and Richmond rd is anzac highway then i would imagine traffic trying to get off the motorway at anzac highway would bank up onto the motorway itself. on the SE freeway for example between crafers and Stirling there's about 800m between those entry/exit points. this motorway runs directly through the spine of a major city and cannot be considered as a freight only corridor.

[Nort]

while there can be opposing arguments as to whether a road is a local road or not the reality is that if there aren't sufficient entry exit points on this corridor it will just lead to congestion at entry exit points. as an example northbound if the only entry exit point between tonsley and Richmond rd is anzac highway then i would imagine traffic trying to get off the motorway at anzac highway would bank up onto the motorway itself. on the SE freeway for example between crafers and Stirling there's about 800m between those entry/exit points. this motorway runs directly through the spine of a major city and cannot be considered as a freight only corridor.

They do discuss this in the survey about the area, too few entry/exit point leads to them being a bottleneck, however too many leads to people using the motorway for short trips it isn't intended for.

[mattwinter]

Given the tunnel ends just north of Cross Road anyway I would have thought it would make sense to make the tunnel slightly shorter and do a new cross road / south road interchange while also grade separating the train line.

The northbound on-ramp and south bound off-ramp under the tram overpass wouldn't be needed then either.

I'd hope grade separating the train line at Emerson is high on the agenda anyway. Got to be as important if not more so than ones like Brighton Road. I'd hate for the north south motorway to make grade separation at Emerson even harder / impossible.

I reckon that northbound ANZAC highway exit is going to be nuts with the current plan. Note that north-bound Richmond Road traffic, north-bound airport traffic and northbound city traffic all has to get off the expressway at ANZAC highway under the current proposal. Southbound there are four off ramps between Grange Road and Darlington but northbound only one? Surely not a smart idea.

[aceman]

Given the tunnel ends just north of Cross Road anyway I would have thought it would make sense to make the tunnel slightly shorter and do a new cross road / south road interchange while also grade separating the train line.

The northbound on-ramp and south bound off-ramp under the tram overpass wouldn't be needed then either.

I'd hope grade separating the train line at Emerson is high on the agenda anyway. Got to be as important if not more so than ones like Brighton Road. I'd hate for the north south motorway to make grade separation at Emerson even harder / impossible.

I reckon that northbound ANZAC highway exit is going to be nuts with the current plan. Note that north-bound Richmond Road traffic, north-bound airport traffic and northbound city traffic all has to get off the expressway at ANZAC highway under the current proposal. Southbound there are four off ramps between Grange Road and Darlington but northbound only one? Surely not a smart idea.

I'm certain that if anzac highway is the only exit option between tonsley and Richmond rd then the far left lane will bank up on the motorway with cars trying to get off. god help us if there's an accident in the southern tunnel. you'll be stuck in there for hours.