Remember that we have a no new level crossings policy. Does that give an idea of how much of a priority level crossing removal should be?
Your interest in asking questions and seeking the wisdom of others is quite appreciated.
As I have already noted, Leader St and other crossings are slated to get upgrades, not replacement/removal. That should answer your question about the level of priority placed on replacing/removing level crossings.
Neither SA or Victoria has a policy on removing level crossings, only one-off projects. Even the big Andrews vanity project is a one-off project, not a long-term policy, and the work will come to a halt when it is either completed or cancelled.
Level crossing removals do unlock capacity. For example, removing the Leader and Victoria Street level crossings will allow more train services to and from Adelaide through Goodwood. Are either of these level crossing quiet enough that they could simply be closed, at least after grade separation of the Cross Road ones?
If you look at a map, you will note that Leader St and Victoria St are necessary local access routes linking parts of the community which would otherwise be divided up into ghettoes if all level crossings were to be closed. Just because they are quiet does not mean they are unnecessary.
The level crossing signals at Leader St and Victoria St are activated far enough in advance that trains don't need to stop and wait for the gates to come down, so they do not constrain rail capacity through there. Motorists know that the railway has priority (as you noted yourself) and that there are many trains during the peak hours, so they generally avoid those crossings in favour of the major roads for through journeys.
One might wonder why it wasn't upgraded long ago. Quadruplication of railway track has been a reason for grade separation even before the growth of motor traffic. All sections of the Melbourne suburban with more than three tracks and Sydney suburban with more than two are all grade separated.
Just to clarify, the upgrades at Leader St are to improve the safety of the existing crossing for the increased use by pedestrians and cyclists in recent years, NOT grade separation.
The traffic volumes on Leader St do not justify grade separation.
Suppose you convert the Grange Branch to light rail (possibly still keeping heavy rail services to Port Adelaide). That level crossing will still remain.
I was thinking more of a bus route, or perhaps an extension of the proposed tram line to Adelaide Airport and Henley Beach, than conversion of the existing Grange corridor. The line is only still running because no politicians have had the guts to put it out of its misery.
I know this may have been used as an excuse but since trains get priority at level crossings, surely a railway should be more important. It seems that a grade separation of existing level crossings should be prioritised over grade separation of road junctions as long as there is a commission not to build new level crossings.
South Road is a far more important transport corridor than the Seaford line even today, and this was certainly also the case when the overpass was constructed back in the early 1980s. This was shown most effectively in 2013, when the line was shut down for just short of a year and everybody proved to themselves that they could cope without it.
By putting South Road through traffic on the overpass, both of South Road and the railway get an unhindered run through the junction - as you correctly note, the railway has priority there and does not need to take its turn at the intersection. Had the railway been put on an overpass back then, only the railway would get to go through unhindered while South Road through traffic would be held up at the intersection.
Traffic volumes on all three of the corridors meeting there have increased since then, and so it is correct that this will be slated for full replacement when the next section of the North-South Motorway is built. The current DPTI preferred option is to replace it with the railway going over the top, Cross Road and local South Road traffic at surface level and the North-South Motorway in the trench.
If you realign the railway, that level crossing will go anyway.
We are in agreement on this. The future of the North-South Corridor dictates that the railway will have to get grade separated there as part of the project, and it is at this point that any work to realign the railway would be done.
What the final arrangement at Cross Rd/South Rd/Seaford Rail Line will be has not been decided and when it does get decided, it is possible (even probable) that it will change. Different scenarios that I have seen include realigning the railway to eliminate the tight curve between Edwardstown Station and the intersection. Various things with that realignment included grade separation (up and down), utilisation of the old Hills site, replacement of Edwardstown Station, and so forth. All these things are being considered now for future projects. There is NO hard and fast policy one way or another to set in concrete any one plan.
I have it on good record that the DPTI preferred option is to build an overpass on the current alignment, considering that the likely arrangement of the North-South Corridor through the Edwardstown sector will be to have the grade separated Motorway in a trench and the local roads at surface level just like it is on the next grade separated sections to both the north (Anzac Highway underpass) and south (Darlington Upgrade).
I would be genuinely astonished if anything other than the DPTI preferred option were to be built there, any decision to reroute the whole rail corridor would have to involve considerable political interference as it certainly wouldn't have a better BCR than a simple overpass which gets the job done with minimum fuss and no more than a couple of weeks closure.
Shouldn't this be in the Armchair operators thread
I'm not always in agreement with you but there's no doubt this time.
I've reported the OP for that purpose of being sent downstairs to dwell with the magtubes, since there is some doubt over the OP's willingness to engage on a rational basis.