[U/C] M2 North-South Motorway

[Mr Messy]

Northern connector interchange maps are up
https://www.infrastructure.sa.gov.au/ns ... hange_maps

[Goodsy]

Northern connector interchange maps are up
https://www.infrastructure.sa.gov.au/ns ... hange_maps

Interesting choice for Bolivar

[rhino]

Northern connector interchange maps are up
https://www.infrastructure.sa.gov.au/ns ... hange_maps

Interesting choice for Bolivar

Indeed - roadworks for roadworks' sake. Interesting cartography showing East at the top when mapping a north-south road. Confusing, much!

[SBD]

Northern connector interchange maps are up
https://www.infrastructure.sa.gov.au/ns ... hange_maps

1) Can anyone see how the new plans get workers in and out of the Bolivar treatment plant? I believe it's currently on the road past Krispy Kreme that will become the southbound interchange but doesn't obviously continue under the freeway.
2) Does anyone know how much traffic currently uses Port Wakefield Road other than from Salisbury Highway and turns onto the Northern Connector? As the Northern Interchange will no longer support that movement, anyone who wants to do it will need to use Bolivar or Waterloo Corner interchanges (or Heaslip Road). Perhaps that traffic contributes to the complexity of the Bolivar interchange.

[alexczarn]

No left turn from the northbound M2 onto the A9 Pt River Expwy?

[Kasey771]

No left turn from the northbound M2 onto the A9 Pt River Expwy?

That’s a step backwards


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[Goodsy]

No left turn from the northbound M2 onto the A9 Pt River Expwy?

I don't think they've highlighted parts of the interchanges that are already built. The Northern Interchange is also missing the left turn onto the NEXY from Port Wakefield Road

[[Shuz]]

I don't even understand the rationale behind half of those interchange designs. They're supremely awful.

[SBD]

I don't even understand the rationale behind half of those interchange designs. They're supremely awful.

The caravan park has a supremely odd-shaped block of land with a tool shed in the corner. I can only assume that they would not come to the party to allow a sufficiently smooth bend for the left turn to have come off the freeway and joined the new Bolivar Road intersection. Instead, the road train parking at OTR needs some sort of treatment that isn't shown on the plan, and presumably traffic lights will be needed at PWR and Hodgson Road which is already considered a bit of a black spot.

[rhino]

The caravan park has a supremely odd-shaped block of land with a tool shed in the corner. I can only assume that they would not come to the party to allow a sufficiently smooth bend for the left turn to have come off the freeway and joined the new Bolivar Road intersection.

This can be overcome by inserting a roundabout, as has been done in numerous places. It seems PWR is to have another set of traffic lights, instead

[Kasey771]

The caravan park has a supremely odd-shaped block of land with a tool shed in the corner. I can only assume that they would not come to the party to allow a sufficiently smooth bend for the left turn to have come off the freeway and joined the new Bolivar Road intersection.

This can be overcome by inserting a roundabout, as has been done in numerous places. It seems PWR is to have another set of traffic lights, instead

Isn't there already a set of lights for Bolivar Rd on PWR? so the intersection just gets bigger, not a new set of lights.

[SBD]

The caravan park has a supremely odd-shaped block of land with a tool shed in the corner. I can only assume that they would not come to the party to allow a sufficiently smooth bend for the left turn to have come off the freeway and joined the new Bolivar Road intersection.

This can be overcome by inserting a roundabout, as has been done in numerous places. It seems PWR is to have another set of traffic lights, instead

Possibly - it's hard to tell when the plans don't show what goes over or under what else - would a roundabout have ended up too close to a bridge? This plan also appears to introduce another bridge where the southbound off-ramp at Bolivar crosses the (northern half) of the southbound on-ramp.

It's also disappointing that these new plans don't show how the shared path crosses or gets round the interchanges, and the original project plan with the pink line has been removed from the website. So now it's not clear how the shared path will cross PWR at the Northern interchange, nor how it will cross the abomination of Bolivar interchange or Salisbury Highway. The Stuart O'Grady Bikeway gets a reasonable amount of traffic at times as it's over 20km with only seven road crossings in five places, but at present it doesn't really go anywhere. The extension along Northern Connector will make it a useful route to get between the northern and western suburbs in a protected, off-road way for long-distance runners/joggers as well as cyclists.

[alexczarn]

The caravan park has a supremely odd-shaped block of land with a tool shed in the corner. I can only assume that they would not come to the party to allow a sufficiently smooth bend for the left turn to have come off the freeway and joined the new Bolivar Road intersection.

This can be overcome by inserting a roundabout, as has been done in numerous places. It seems PWR is to have another set of traffic lights, instead

Isn't there already a set of lights for Bolivar Rd on PWR? so the intersection just gets bigger, not a new set of lights.

No this would be an extra set, just south of Bolivar Rd on PWR, for the Sthbound off; and superfluously, another southbound on.

[mawsonguy]

I'm glad to see that somebody woke up to the fact that, with the elimination of the Globe Derby Interchange, the original plans did not provide for any southbound off ramp between Waterloo Corner Interchange and Grand Junction Road. A southbound off ramp at Bolívar was a necessity. Unfortunately, the close proximity of the caravan park to the interchange causes problems. Off ramps are designed with curves in order to slow traffic. There is insufficient room between the back fence of the caravan park and the southbound carriageway to accommodate an S bend in the offramp which means it cannot connect with a roundabout on the overpass. Likewise, there is insufficient room between the overpass and the southern boundary of the caravan park to allow the offramp to merge with the eastbound carriageway on the overpass. The 135° turn would also be dangerous. Traffic coming from the offramp and immediately moving over to the right before the Port Wakefield Road lights would also be an issue. That said, the current design is sub optimal. It requires southbound traffic to negotiate a roundabout, turn left at traffic lights on Pt Wakefield Rd and then turn right at a second set of traffic lights in order to get onto Kings Road. I also can't see the need for a second on-ramp connected to the roundabout. Surely northbound traffic on Pt Wakefield Road can easily travel another hundred metres to access the on-ramp at the Kings Road intersection. A better solution may have been to have the offramp north of the caravan park with a bridge over the Pt Wakefield Road northbound carriageway onto the southbound carriageway on Pt Wakefield Road so that southbound traffic can enter Pt Wakefield Road before the Kings Road intersection.

[drsmith]

The Bolivar Road interchange looks like an attempt to integrate two main objectives, a free-flowing trumpet design with a northbound exit/entry to the OTR fuel stop. The southbound entry from Bolivar Road will presumably be braided (grade separated) from the southbound exit to the Hodgson Road roundabout to avoid a conflict there. That's not 100% clear from the diagram as bridge structures aren't specifically shown.

The controlled (signalised) left exit from Hodgson Road (no slip lane) onto PWR northbound may be sufficient as this would be a low volume movement or essentially, a second chance to exit the expressway route southbound to the east before Grand Junction Road. Without this, signage at the northern interchange would direct traffic intended to continue down PWR southbound to do so there. That may still be the case with the Hodgson Road exit to PWR a second chance for those who mistakenly continue along the expressway route from the northern interchange.

More broadly, southbound access to/from OTR may be a recognition that once the north/south corridor is complete, there would otherwise be no fuel stop access between Nuriootpa (Lower Light on PWR) and Old Noarlunga. If that's the case, a northbound fuel stop may be built adjacent to the northbound carriageway between the Bolivar interchange and the Waterloo Cornet interchange.

Present interchange ramps at the northern end and southern end that are not shown in the maps may be reflective that they don't require modification rather than their closure. This includes PWR southbound to the Northern Expressway northbound, South Road Superway southbound to the Port River Expressway westbound and Salisbury Highway westbound to South Road northbound under the Superway.

Hopefully, more design detail will soon be published for the updated design and/or an updated video render.