Auckland Transport have lodged notice of requirement and resource consent documents for the Newmarket Crossing project which is a bridge from Cowie St to Laxon Tce and is so that the Sarawia St level crossing can be closed. The level crossing is currently the busiest in the country in terms of train movements and its proximity to the Newmarket Station and junction impacts on services across the rail network. For more information on here is a good fact sheet from Kiwirail that explains the rail impacts.
The bridge and approaches will be fairly narrow and designed to keep vehicle speeds down which makes sense giving this is a local road connect to a handful of households. Below is the concept designs for the road. There is a footpath on the northern/eastern side of the crossing and it appears the intention is for cyclists to share the traffic calmed road with vehicles.
There will also be connections to Newmarket Park and what appears to be a link down towards the train tunnels. I imagine that’s initially just for access for Kiwirail maintenance crews however longer term the local board want to open up the disused tunnel to use for a walking and cycling route.
And here is the an image from the Notice of Requirement of the proposal showing the design footprint
Some of the residents of Cowie St have been particularly unhappy that the connection will be via their street. You may recall they even went as far as proposing their own connection of an underpass from Sarawia St. Below is an excerpt from the application assessing their proposal.
In June 2013 representatives from the PCC and CSRA approached AT with a proposal for an alternative underpass alignment. The underpass was proposed as an alternative option to allow closure of the Sarawia Street crossing while retaining vehicle access to Laxon Terrace and Youngs Lane. It was suggested by the PCC and CSRA that this would be more acceptable to residents.
Following a decision made by the AT Board to select the Cowie Street Over Bridge option as the preferred option for the Sarawia Street level crossing closure in December 2013, there was a request from the CSRA to present an alternate underpass proposal. The underpass proposal presented by the CSRA (Figure 14) followed a different road alignment to that investigated by AT but most closely resembles the AT option shown in Figure 13 above. The CSRA proposal was subject to both an internal AT review as well as an external expert review (Opus), neither of which substantiated the underpass proposal as a superior option to the Cowie Street Over Bridge option.
AT’s assessment of both the April 2014 and August 2014 CSRA reports concluded that they did not convincingly make the case for overcoming the principal issues associated with an underpass at Sarawia Street that were:
- High risk and disruptive construction phase when compared to alternative options.
- Most challenging CPTED concerns compared to alternative options.
- Significant traffic safety challenges when compared to alternative options.
- A low benefit-cost ratio when compared to alternative options.
AT concluded that overall the underpass option, although a technically feasible option, still retains significant construction risks, rail disruption, CPTED concerns and traffic safety challenges. AT did not agree with the CSRA underpass design assumptions that resulted in the substantially lower cost estimate prepared for the CSRA report.
Recommended remediation for the identified CPTED issues included footpath widening, underpass widening, chamfering of approach, allowance for sightline issues relating to steep vertical grades, and the installation of a convex mirror. Similarly, remediation for traffic safety issues in the concept design would require widening of the underpass and chamfering of the approaches to improve vehicular sightlines and turning circles.
Several deficiencies were identified in the underpass concept design presented by the CSRA relating to structural and geotechnical design. Remediation for these deficiencies was considered to result in increased section sizes for the over-road bridge structure relative to those shown in the design presented by the CSRA, the use of piling at the abutments, and more sophisticated abutment articulation to provide seismic resilience, among other design modifications.
Identified constructability issues related to Block of Line requirements, KiwiRail access, lifting of precast elements, and sheet pile construction. These issues were considered by AT to be further compounded by all the changes to the current underpass concept design required to arrive at a viable solution. The resulting final underpass design would therefore be markedly different from the proposed concept design, with considerably increased construction time and disruption to the rail network
AT considered that the Cowie Street Bridge Option remained a superior option to the underpass option prepared for the CSRA.