The space constraints and accommodation for the many other needs (e.g. walking/cycling) at Melling don’t allow for a roundabout-style design such as at Maungaraki or Haywards. We had investigated this as part of the initial project stages, but the proximity of the hills, rail line and river mean there’s simply not enough room unless we make major cuts into the western hills (which would have significant environmental and cost impacts). We also have to consider the Waiwhetū aquifer, which is close to the project site and supplies up to 70% of Wellington’s water during summer, as well as the Wellington Fault.

Other benefits of the revised design include:

• Fewer conflicting movements for traffic entering and exiting Lower Hutt – this improves both efficiency and safety
• Integrates better with the stopbank work already under way as part of the wider Te Wai Takamori o Te Awa Kairangi programme
• Wider shared paths and shorter pedestrian crossings for people travelling to and from the Western Hills
• Smaller bridge footprints
• Better access to public transport through improved park and ride facilities and a relocated Melling train station
• Significant portions can be built ‘off-line’ – meaning disruption to SH2 traffic will be minimised during construction.

The detailed design phase is now under way, where we will continue to identify further cost or efficiency savings. This is standard practice and will continue until construction begins.

Last updated: 4 Apr 2025