Toll Roads in Adelaide

[rhino]

Claybro, I believe it's 17km from Darlington to Regency Park. On a non-stop 60km/hr road, this would take 17 minutes. On a freeway, travelling at 120km/hr (which is above the speed limit) it would take 8.5 minutes, a saving of only 8.5 minutes, and only if you travel the whole distance. If you are using the freeway to get into the city, you will save approx 4 minutes. There really isn't enough justification for spending the huge ammount of money to build a freeway as opposed to a non-stop controlled access 60km/hr road, despite a vocal minority.

[muzzamo]

There really isn't enough justification for spending the huge ammount of money to build a freeway as opposed to a non-stop controlled access 60km/hr road, despite a vocal minority.

What about the difference in maxium capacity between a freeway and a non-stop controlled access road? Surely a freeway (at 100km/hr) can handle more cars per hour, meaning a greater capacity, less congestion and more futureproofing (induced demand issues aside).

[Aidan]

There really isn't enough justification for spending the huge ammount of money to build a freeway as opposed to a non-stop controlled access 60km/hr road, despite a vocal minority.

What about the difference in maxium capacity between a freeway and a non-stop controlled access road? Surely a freeway (at 100km/hr) can handle more cars per hour, meaning a greater capacity, less congestion and more futureproofing (induced demand issues aside).

Surprisingly enough, no. At higher speeds braking distances mean the vehicles have to be further apart. There's not much difference between capacity at 60 and 80km/h, and above that it declines.

Of course that's capacity per lane. A freeway could still have more capacity with more lanes of free flowing traffic. But if capacity's the issue, railways are likely to be the best solution.

[claybro]

to get into the city, you will save approx 4 minutes. There really isn't enough justification for spending the huge ammount of money to build a freeway as opposed to a non-stop controlled access 60km/hr road, despite a vocal minority.

I dont believe the entire transport industry(one of the largest employers in the state), including trades, couriers and taxis etc to be a vocal minority. Saving 4 mins into the city is nothing to do with this as this route is not designed to deliver peak hour commuters into the city. That is what trains are for. I have looked at this mainly from a transport industry point of view. If we dont bite the bullet and plan this route properly now, we will be at this point again having the same discussion in less that 20 year,as we are 20-30 years after south road was last upgraded. Only thing is by then, it wll be much harder and more expensive to upgrade this corridor.

[Aidan]

to get into the city, you will save approx 4 minutes. There really isn't enough justification for spending the huge ammount of money to build a freeway as opposed to a non-stop controlled access 60km/hr road, despite a vocal minority.

I dont believe the entire transport industry(one of the largest employers in the state), including trades, couriers and taxis etc to be a vocal minority.

Do you believe them to be a majority? Or just not vocal?

You're making the mistake of assuming the entire transport industry agree with you. Hasn't it ever occurred to you that others in the industry have different priorities?

Saving 4 mins into the city is nothing to do with this as this route is not designed to deliver peak hour commuters into the city.

Who said anything about peak hour commuters?The 4 minutes is under free flow conditions. The issue is off peak travel time for those trades, couriers and taxis.

That is what trains are for. I have looked at this mainly from a transport industry point of view. If we dont bite the bullet and plan this route properly now, we will be at this point again having the same discussion in less that 20 year,as we are 20-30 years after south road was last upgraded. Only thing is by then, it wll be much harder and more expensive to upgrade this corridor.

By then the corridor will have been upgraded, so I doubt the calls to spend billions to turn it into a freeway to save eight minutes would be taken seriously enough for there to be much debate.

If we do it your way, the discussions in 20 years would be sbout how long it's taking to get it finished and how much it's ruined the inner suburbs.
If we do it my way then after it's grade separated and local traffic lanes completed, that will be the end, and it will never need upgrading again (aside from minor safety upgrades). When it eventually becomes inadequate we can build a tollway under the Morphett Road corridor, which would serve the airport directly as well as being a shorter route between the southern suburbs and the port.

[claybro]

When it eventually becomes inadequate we can build a tollway under the Morphett Road corridor, which would serve the airport directly as well as being a shorter route between the southern suburbs and the port.

Gee, that won't cost much.

[claybro]

. When it eventually becomes inadequate we can build a tollway under the Morphett Road corridor

Furthermore Aidan, I'm a bit confused by this. Part of your discussion is about a freeway on South road being "overengineering" and too much expense, and yet here you seem to acknowledge at some point in the future, your solution for limited South Road upgrade will become inadequte, and propose an even more expensive, over engineered solution of tunnels under Morphett Road/Airprt ETC. Bearing in mind that in 30 years time the government is propsosing and addtional population in Adelaide of an extra 300000 residents I think a freeway needs to start construction NOW and via the least expensive option.

[Aidan]

When it eventually becomes inadequate we can build a tollway under the Morphett Road corridor, which would serve the airport directly as well as being a shorter route between the southern suburbs and the port.

Gee, that won't cost much.

Of course it will be expensive, just as Brisbane's airport tollway is expensive. But it will also bring much greater benefits, especially to the transport industry, so I'm rather puzzled as to why you oppose it.

Furthermore Aidan, I'm a bit confused by this. Part of your discussion is about a freeway on South road being "overengineering" and too much expense, and yet here you seem to acknowledge at some point in the future, your solution for limited South Road upgrade will become inadequte, and propose an even more expensive, over engineered solution of tunnels under Morphett Road/Airprt ETC. Bearing in mind that in 30 years time the government is propsosing and addtional population in Adelaide of an extra 300000 residents I think a freeway needs to start construction NOW and via the least expensive option.

With only another 300000 residents, a limited South Road upgrade should be sufficient. But we're unlikely to stop growing there, so we have to consider the long term needs to avoid making false economies. Future needs and how best to accommodate them should always be considered, but minimizing costs now, when many other important projects are cancelled or held back due to lack of funding, is far more important than minimizing them in the future when availability of funding is unlikely to be such a big constraint.

Overengineering is building something to much greater specifications (and hence much more expensive) than what's actually needed. The tollway I'm proposing is not just a solution to South Road problems, but also a much faster way of accessing the airport, a faster and shorter route to the port and an alternative to the increasingly busy Brighton Road corridor. But most importantly we won't have to spend any money now - we can wait until it's needed. And unlike normal freeways, tunnels aren't likely to get significantly more expensive the longer we wait.

[claybro]

The South Road route aligns with most of the heavy/light industrial areas of Adelaide, in the South, West and North. South road passes some 2km from the Airport entrance via the wide Sir Donald Bradman Road. The Port is accesable from South Road via....The PREXY. Your proposed tollway under Morphett Road and the airport ETC passes through.....well suburbia. Not even the over the top MATS plan envisaged such a route.

[Aidan]

The South Road route aligns with most of the heavy/light industrial areas of Adelaide, in the South, West and North. South road passes some 2km from the Airport entrance via the wide Sir Donald Bradman Road. The Port is accesable from South Road via....The PREXY. Your proposed tollway under Morphett Road and the airport ETC passes through.....well suburbia. Not even the over the top MATS plan envisaged such a route.

I'm well aware fo the geography of Adelaide. Of course you can access all these places by road. It's just that the roads are rather indirect, particularly to the airport from the south. BTW your 2km figure is wrong and SDBD isn't particularly wide.

Underground tollways pass under suburbia, not through it. They were not a practical option in the 1960s when the MATS Plan was written.

[claybro]

After all this debate, I guess you are correct in that your proposal for a limited upgrade of South Road will be the chosen option in the near term. This will not be able to be a tollway. It will remain the only route with sufficient traffic volume in near future to even consider a tollway in Adelaide. Once this route is widened with removal of most if not all intersections, it will so closely resemble an expressway, that the call will inevitably be to upgrade it again.(as per the Southern expressway) It will be too tempting by the govenrment of the day to simply again widen this route and further limit local access. once the substantial amount of funds are comitted even to the limited upgrade required over the next 10-20 years, I dont believe th north south route would then be duplicated with your proposed tollway. The airport in Adelaide is Australias, and one of the worlds most accesable and does not require freeway/tollway access.

[Waewick]

Pardon my ignorance

but wouldn't a tollway be created to avoid the upgrade of South Road further?

[Aidan]

After all this debate, I guess you are correct in that your proposal for a limited upgrade of South Road will be the chosen option in the near term. This will not be able to be a tollway. It will remain the only route with sufficient traffic volume in near future to even consider a tollway in Adelaide.

No it won't. Glen Osmond Road is also a suitable candidate.

Once this route is widened with removal of most if not all intersections, it will so closely resemble an expressway, that the call will inevitably be to upgrade it again.(as per the Southern expressway)

The call to upgrade the Southern Expressway was to make it two way. There wasn't any significant call to widen the existing carriageway even though it was ultimately decided to widen it anyway.

It will be too tempting by the govenrment of the day to simply again widen this route and further limit local access.

It may be simple to say, but doing so would be extremely complicated and expensive. Adding yet more lanes would require a huge amount of building demolition, plus a lot of expensive infrastructure would have to be replaced (widening overpasses and underpasses is not cheap and couldn't be done without a huge amount of disruption). And the benefits wouldn't actually be that large. It would be easier to ignore those calls and listen instead to calls for upgrades on Marion and Goodwood roads, as together those would be of greater benefit yet much chesper. Realignments (Daws/Springbank and both ends of Holbrooks) and tram bridges could make a great deal of difference.

But once we have a successful tollway, attention is likely to turn to where we can build more.

once the substantial amount of funds are comitted even to the limited upgrade required over the next 10-20 years, I dont believe th north south route would then be duplicated with your proposed tollway. The airport in Adelaide is Australias, and one of the worlds most accesable and does not require freeway/tollway access.

Though it's not a requirement, it's something the airport would benefit from.

[[Shuz]]

You spin me right round baby, right round like a record baby, right round.

[ml69]

Just had a thought out of left-field in relation to a north-south corridor alignment, one which I don't think anyone has been proposed before.

From the Darlington intersection of the Southern Expressway, what about a surface expressway (tolled) following Sturt Creek? From there, some property acquisition will be required south of Morphettville Racecourse and along the eastern boundary of the racecourse. A short tunnel will be required under the Glenelg tramline and Anzac Hwy, before surfacing and following the Glenelg railway alignment to eventually join up with a widened James Congdon Drive.

This appears to be wide enough for a 3x3 lane expressway, with noise walls restricting traffic noise for nearby residents. This would make it possible to travel at say 80kmh from the Southern Expressway to James Congdon Drive.

What about the impact on Sturt Creek I hear you say? Well, it's a concrete drain at the moment, not particular scenic. The creek can be contained in a drainage channel underneath the expressway.

There are a number of advantages of this:

- HIgh speed (say 80kmh) 3x3 lane traffic corridor
- If built as a private tollway, no/minimal upfront investment required by the State Government. Even if it needed a "shadow toll" subsidy from the State Govt to make it financially viable, this is still cheaper than the government funding by itself
- No impact on South Rd businesses
- Minimises traffic impact during construction period (likely to be 3-4 years)
- New roadway increases capacity and will better future-proof our north-south corridor than upgrading South Rd
- Lower cost of surface construction vs tunnelling

Of course there will be points to criticise, such as impact on local residential communities where the tollway will pass through. However, I think the impact is not as big as taking out huge swathes of South Rd properties.