Tunnel under the airport ASAP!

[Aidan]

I've finally thought of a way we could take advantage of Covid:
With very few aircraft using Adelaide Airport at the moment, and widebodies in particular likely to be seldom seen this year and next, there's far less need to keep the main runway open for its full length. Which means we have a rare opportunity to build cut and cover tunnels, enabling Morphett Road and Richmond road to be extended directly to the airport terminal much more cheaply than the cost of the bored tunnels which would otherwise be required.

With record low interest rates, and probably never to be repeated low construction costs, now would be the ideal time to invest in Adelaide's future. And there's even the possibility of toll revenue, as many people would normally be averse to paying tolls would gladly pay for the convenience of not having to leave for the airport so soon!

[Nort]

I've finally thought of a way we could take advantage of Covid:
With very few aircraft using Adelaide Airport at the moment, and widebodies in particular likely to be seldom seen this year and next, there's far less need to keep the main runway open for its full length. Which means we have a rare opportunity to build cut and cover tunnels, enabling Morphett Road and Richmond road to be extended directly to the airport terminal much more cheaply than the cost of the bored tunnels which would otherwise be required.

With record low interest rates, and probably never to be repeated low construction costs, now would be the ideal time to invest in Adelaide's future. And there's even the possibility of toll revenue, as many people would normally be averse to paying tolls would gladly pay for the convenience of not having to leave for the airport so soon!

I'm unsure how it follows from reduced aircraft numbers that the runways full length isn't required.

[[Shuz]]

Logic isn't really Aidan's strong suit...

[SRW]

The airport is already proposing connections to these roads for rideshare and freight vehicles without the need for tunnels. It's unclear to me what benefit general access would deliver for the cost.

If you were arguing for a Morphett Road connection to the north of the airport (to maybe Findon Road) that might be more interesting as an arterial alternative to Marion and Tapley's Hill roads. But still inconceivably costly for the benefit.

[Aidan]

Logic isn't really Aidan's strong suit...

Genuinely curious: what gives you that impression?

[Aidan]

I'm unsure how it follows from reduced aircraft numbers that the runways full length isn't required.

Long runways are really only needed for long haul flights, but there are very few of those at the moment.

I'm sure a commercial arrangement could be arranged with the airlines to keep those few services running by making a fuel stop at another Australian airport on the way out. Because there are so few flights, it shouldn't be that expensive.

[Aidan]

The airport is already proposing connections to these roads for rideshare and freight vehicles without the need for tunnels. It's unclear to me what benefit general access would deliver for the cost.

AIUI what the airport is proposing involves general access on an indirect route.

If you were arguing for a Morphett Road connection to the north of the airport (to maybe Findon Road) that might be more interesting as an arterial alternative to Marion and Tapley's Hill roads. But still inconceivably costly for the benefit.

A connection to Findon Road would be part of the eventual aim, along with grade separating Morphett Road and connecting it to the Southern Expressway near Majors Road. But that's decades into the future. Meanwhile, faster connections to the airport would bring enormous benefits to all its users in the southern suburbs.

[Nort]

I'm unsure how it follows from reduced aircraft numbers that the runways full length isn't required.

Long runways are really only needed for long haul flights, but there are very few of those at the moment.

I'm sure a commercial arrangement could be arranged with the airlines to keep those few services running by making a fuel stop at another Australian airport on the way out. Because there are so few flights, it shouldn't be that expensive.

Adds a lot of delays and expense, which if it was a worthwhile project could be worth it, but doesn't seem like it would stack up in this case.

[ynotsfables]

Logic isn't really Aidan's strong suit...

Oh and what’s your logic?

[Aidan]

Having thought about it a bit more, I've realised a straight extension of Morphett Road would not be suitable for the cheapest form of tunnel (which involves digging a trench, lifting in a box culvert and backfilling) because it would also affect the crosswind runway. However a tunnel from the central airport area (SW of the terminal building) to the (as yet unbuilt) road linking Morphett Road and Richmond Road would bring similar immediate benefits and enable about 2.5km of runway to be kept open at all times.

Doing this would be great for buses - it would reduce the J7/J8 journey time by ten minutes, as well as enabling buses to get from the airport to Glenelg more quickly.

[1NEEDS2POST]

You might be interested in this thread. There is official talk of an "airport link" with the North-South motorway. https://www.sensational-adelaide.com/fo ... start=4920

Another totally different idea: instead of a tunnel, we could have a lowered O-Bahn along Keswick Creek. It's too narrow for a multi-lane road, but an O-Bahn should fit. Some backyards might need to be acquired.

Buses come from the city on the red line, then enter the O-Bahn in the median on James Congdon Drive. The blue line is the O-Bahn to the airport. The intersection with Sir Donald Bradman Drive would need to be modified to allow buses to turn onto James Congdon Drive.

[Aidan]

Another totally different idea: instead of a tunnel, we could have a lowered O-Bahn along Keswick Creek.

An O-bahn that floods every time it rains???

[rev]

If they buy up the properties along that stormwater drain, they could build a non-stop road.
Bit of a funky interchange linking it to the NSM and JCD, run the road around the northern end of the airport and some on/off ramps at Sir Richard Williams ave..and you have your airport link. Marion Road could be an underpass.
Would be easier then upgrading SB drive or HBR both of which would cause significant traffic disruptions.

Could also work for an express rail link between the airport and city.

[Ho Really]

If they buy up the properties along that stormwater drain, they could build a non-stop road.
Bit of a funky interchange linking it to the NSM and JCD, run the road around the northern end of the airport and some on/off ramps at Sir Richard Williams ave..and you have your airport link. Marion Road could be an underpass.
Would be easier then upgrading SB drive or HBR both of which would cause significant traffic disruptions.

Could also work for an express rail link between the airport and city.

Buying up properties would be the best solution for either a road as you suggest rev or the rail link that I have been saying for years. Aidan I bet if you wanted you could come up with solutions for a drain. As far as I know (correct me if I'm wrong) the Keswick Creek is mostly already diverted. It could be taken further and all water eliminated completely. The drain is perfect for a single track and a loop where there is the access road and will be grade separated at Marion and South Roads. No intermediate stops between Airport and City unless one wants two stations under these two main roads.

Cheers

[Nort]

The Keswick creek is an important part of stormwater removal for the area, with the area considered especially susceptible to once in a hundred year floods.