While looking at Auckland Transport’s website recently I came across a now closed consultation relating to the Porters Ave level crossing and how it is affected by the CRL. Some of the information included in the consultation is quite technical and may be of interest to readers.
As originally planned the CRL was to have had a station underneath the southern end of Symonds St before travelling through a flat junction to the connections towards Grafton and Kingsland. Due to the grades involved the tracks from the CRL would have been in a cutting about 4m below the current track level at Porters Ave so it wouldn’t have taken much to bridge over the tracks to provide a grade separated crossing. This is shown below.
AT say this design is no longer possible due to the changes made dropping the Newton Station and creating a grade separated junction in its place. As a result, the tracks will be a lot closer to the surface and as such would need a higher bridge. The problem is the proximity of the crossing to New North Rd and as such the ramps needed to reach the bridge would result in a 2-3m difference in height at the intersection. As such AT needs a different solution.
A traffic assessment found the crossing was used by just over 2,800 vehicles a day with hourly peak volumes as shown below. It also found that the impact of closing the crossing would send traffic to Dominion Rd and Mt Eden Rd which would result in some all increases on nearby roads but that overall travel times won’t be all that different.
For the consultation AT provided three alternatives. Each were assessed a range of criteria which can be summarised into four groups
- Environmental and social
1. Close the crossing built build a pedestrian/cycle bridge
Given the title, it should be fairly self-explanatory and AT say that this is their preferred option having come out with the best results from the assessment criteria with a total of 12.07.
2. Close the crossing built build a pedestrian/cycle bridge and a road from Fenton St to Akiraho St
This is an extension of the option 1 above and adds a new road connection between Fenton St to Akiraho St. AT say the main issue with it is that it would require new land to be purchased to build the connection and would increase vehicle numbers. From the analysis it wasn’t too far behind assessment of option 1, scoring 11.41
3. Build a new road connection from Ngahura St.
The third option is a departure from the two above and AT also consider it the least favourable option. It would involve building a 120m long bridge from Ngahura St. This option would not only be expensive but also require the removal of the apartment building next to the tracks. In other words, this wouldn’t be cheap (or easy). It had an assessment score of 9.84.
Option 1 does seem like the best of them but it will be interesting to see what feedback AT get. Will they cave and pursue a bridge option like they did just down the road in Newmarket with the Sarawia crossing?
I also wonder when or when we’ll hear about any other level crossing removals. It feels like something not even really on ATs agenda.
Lastly I thought this image (click here for larger version) showing the layout of the area was quite interesting. In the top right you can see a cross section of the rail corridor at a few locations. Also showing is the junction that will be underground and the extension of Ruru St over the new station platform and around alongside the tracks to Mt Eden Rd.