Which permanent rail speed restrictions are too slow?

[somebody]

25km/h approaching Roma St #9
25km/h at the diverge towards the Merivale Bridge at Roma St West Junction
10km/h approaching Central #4
50km/h on the suburbans over the Indooroopilly railway bridge
60km/h on the mains over the Albert Rail bridge at Indooroopilly (bridges could be the other way around)
30km/h (IIRC) leaving Roma St #8
xx leaving Central #4
50km/h though Taringa, Toowong station and Auchenflower station.
50km/h diverging through the crossovers between Milton #1 & #2 and Roma St #8 & #9.
30-40km/h between Roma St and Central on the suburbans
xx km/h reverse diverge from Northgate #4 to Virginia #3

This list is far from complete and a couple of the speeds I'm not 100% sure of.

[mufreight]

All of the above speeds are as a consequence of infrastructure, either curve radius of as in the case of the approach to Roma Street because of a combination of curve radius and diamond crossings made necessicary by the amount of room within the raiul corridor.
To resolve those that you have focused on at this stage a conservitave estimate to remove them and rais speeds to an 80kph median you would be looking at a figure in excess of $1.7 billion.
Being practical that is not realistic.  There are possibly some gains that could be made but the gains relative to the costs are minimal, the costs are not.
Far better that the funds be expended in such a way as to gain worthwhile improvements like CRR.

[somebody]

How did you come up with the $1.7bn figure?

[somebody]

Additionally the 30km/h rising to 40km/h leaving Park Rd bound for the Cleveland line.  It's 25km/h bound for the Beenleigh/Gold Coast lines, but may rise after clearing the points.

It is likely that rectification of all these issues may not be cost effective.  Which is a strong argument why works need to be done correctly in the first instance.  I submit that a number of the proposed limitations would be cost effective to address, however.

[Golliwog]

Yes, in and of themselves, I don't think you'll get a project to go ahead if all its doing is speeding up a small section of track slightly. However, making note of where the problems are certainly provide a benefit as if works were being undertaken that could have any impact on it, rectification works could be undertaken. For example the slow points you just mentioned at the Park Rd junction, I doubt they'll go in to modify anything major for that, however if they ever do anything about grade seperating the junction then I'm sure they could sort out any remaining junctions / redundant junctions.

[petey3801]

25km/h diverge for the airport branch and at the far end of the crossing loop.
25km/h diverge approaching International

Diverge onto Airport branch is 50km/h, not 25km/h.

Approach to International (from the single track section) is 40km/h.

[somebody]

25km/h diverge for the airport branch and at the far end of the crossing loop.
25km/h diverge approaching International

Diverge onto Airport branch is 50km/h, not 25km/h.

Approach to International (from the single track section) is 40km/h.

Those were the main ones I wasn't sure of.  I've removed them from the OP.

[somebody]

25km/h diverge for the airport branch and at the far end of the crossing loop.
25km/h diverge approaching International

Diverge onto Airport branch is 50km/h, not 25km/h.

Approach to International (from the single track section) is 40km/h.

What about the points at the airport end of the crossing loop near Eagle Junction.

[petey3801]

25km/h diverge for the airport branch and at the far end of the crossing loop.
25km/h diverge approaching International

Diverge onto Airport branch is 50km/h, not 25km/h.

Approach to International (from the single track section) is 40km/h.

What about the points at the airport end of the crossing loop near Eagle Junction.

Where the double track goes into single on the branch itself? Also 50km/h.

[somebody]

Ok, thanks.  Trains often seem slow through there, but that could be to do with mistiming of the cross.

[petey3801]

Ok, thanks.  Trains often seem slow through there, but that could be to do with mistiming of the cross.

Towards the airport, yeah, it could be something to do with the cross. Inbound towards the City, the signals are VERY close together from the single-to-double track section of the junction and EJ, so restricted signals = slow right down.