koalaboy wrote:Apologies Aidan for misquoting Fabricator, I am still learning how to use these forums. Based on your reply I can see that you never get anything wrong or make a mistake in life.
We all get things wrong and make mistakes, and people don't hesitate to correct me when I do.
By definition a freeway is a road that is free flowing, or as the government says non-stop. They don't need to be 100km/h, but they need to follow the same principles such as no direct access to the freeway apart from interchanges.
And that's
NOT a principle that South Road needs to follow.
I never said that adjacent intersections needed to be treated the same way, just considered together. There is a big difference. This simply means that your need to draw up a full scheme from end to end, when intersections are closely spaced. Looking a one section in isolation is pointless.
I agree they need to be considered together in that sense, but I don't think that's what the report meant by
considered together.
Aidan wrote:A slip road separated from the main part of South Road by a landscaped strip. If necessary it could be widened and noisewalls constructed.
Widened where? Into their front gardens, by acquiring their land?
No. Widened into where South Road currently is. Possibly at the expense of the median strip, or possibly entirely from the vacant strip of land on the other side of the road.
Not to mention being on the north side of their block, a high noise wall would cast a shadow over their entire front yard.
It is a tradeoff. But the noise wall doesn't have to be big enough to screen out the road entirely - just being big enough to block most of the wheel noise would be a significant improvement. And as the noise walls would be separated from the houses by the landscaped strip and the road, shadowing shouldn't be too much of a problem.
Acquiring a proportion will cost nearly as much as buying the whole block. And suddenly your footprint is becoming no different.
On the contrary, my footprint would be entirely within the available space, not encroaching on the houses at all.
Aidan wrote:Or University Drive.
Have you not seen University Dr in the peak hours? It can’t handle much more traffic, if any at all. Pushing the problem somewhere else and ignoring the impact seems to be your solution for everything. Once again, the solution needs to be looked at in its entirety, not one section in isolation.
I didn't say the impact should be ignored. If University Drive is inadequate to meet the PM peak demand, obviously we should look at why it's inadequate and how that can be addressed. My point was there are options, and people will use the one that best suits them.
Aidan wrote:Impossible??? There are plenty of steeper hills than that in the suburbs! Nor is it the only roundabout at the bottom of a steep hill.
Obviously Aidan you are not aware of these annoying things called design standards and guidelines. Unfortunately, to avoid litigation most professionals have to follow them. Over time standards change to reflect higher standards of safety. In some instances due to the steepness of the existing terrain, there is no other option but to install a sub-standard slope or intersection. But given the terrain in Darlington, your scheme would never be allowed. Even if the grades you suggest were possible, the overpass would not meet the disability act requirements. How would pedestrians cross South Rd at Flinders Dr on your 30% grade bridge?
You think I was suggesting 30% gradients??? Struth, no wonder you oppose it!
I haven't got detailed figures (this was only a conceptual design) but using Google Earth I make it around 10%. That's the same as the bottom section of the street I live on (which ends in a roundabout). There are 3 obvious ways of making it a bit shallower if need be.
As for the pedestrian ramp, it can zig zag if it's too steep - indeed I showed it doing so on the northern side.
Aidan wrote:All of it??? Struth, how shallow do you think gradient and curvature have to be for a road with a 50km/h speed limit?
Yes, all of it. Your spiral is also about 1/3 the minimum radius required, especially coming off an 80km/h design road. You can’t transition design speeds instantaneously from 80 to 50km/h. Maximum grades for 50km/h are about 10% for short sections, but not on approaches to intersections because rear-end crashes will become far more common. You also need sight distance over crests and around corners, all of which will make your scheme bigger. Your overpass will be lucky to come down to ground level before Sturt Rd, Laffer is impossible.
It can branch off South Road earlier if required, and South Road's speed limit does not need to be raised to 80km/h. As for tight curves, is there any reason why advisory speed limits couldn't be used?
Aidan wrote:That figure is based on inadequate public transport, which is one of the things I took exception to.
And you would know this how?
By reading Section 18.4.3.
Politicians win votes more quickly and easily with road projects, about 90% of us drive. Everyone knows PT is the better long-term spend and is more sustainable, but as long as politicians dictate what is built, they will go for the more-popular road projects (for example Southern Exy Duplication).
Duplicating the Southern Expressway is a worthwhile road project that will make a lot of journeys significantly shorter. But building a railway under the City is likely to be similarly popular, as well as increasing train numbers by about a third.
Near doubling of the population in the next 30 years and the existing low-density housing down south will result in growth of traffic. Unless they made PT free, people will still love to drive, particularly with a free-flow road. It’s called induced demand. If the road wasn’t free-flowing and left to clog up, yes people would try PT, but if it is quicker door to door by car, people will continue to drive in big numbers. Look at major cities with good PT, they still have massive traffic chaos.
I'm familiar with growth and induced demand so I'm puzzled as to why you bring up the issue. Surely you know it's an equilibrium situation and attracting more people onto trains will improve traffic flow on the roads? And while speed does make it more attractive, it doesn't actually have to be faster - just competitive.
Aidan wrote:Which is stupid, because it will never be worth constructing extra lanes in the Gallipoli Underpass.
They don’t need to “construct” them, they are already there. It will cost peanuts to convert. Just take out the median, bike lane and parking lane and you have one more lane without changing the bridge or walls. Not stupid at all, it’s called future-proofing. Luckily some people plan for the growth, instead of basing everything on present day for all of their decisions.
Don't you get it? Continual widening South Road is not the best way to accommodate future growth. Making provision for infrastructure we'd be better off without isn't futureproofing.