The Dowse Drive to Petone section of SH2 is bounded by severe physical and operational constraints. Along its western edge, the route is located at the foot of the scarp of the Wellington Fault (also known as the 'western escarpment'). To the east, the Wairarapa and Melling Branch railway lines run the full length of this section of the highway. The section of SH2 between the Korokoro intersection and the Petone overbridges runs through the Korokoro industrial area.
This project was completed in 2009.
A grade-separated interchange with raised roundabout over SH2 at Dowse Drive with a connection to Hutt Road and Dowse Drive; an overbridge replaced the traffic signals at Korokoro connecting Petone and Korokoro; and an upgrade of the section of SH2 between Korokoro and the Petone overbridges providing a raised central curbed median to separate north and southbound lanes.
Work also included the re-arrangement of the Petone Railway Station's existing Park and Ride carpark and the provision of an access bridge over SH2 and service road through to Cornish Street to provide access to the industrial area and Korokoro; no access to private properties from SH2 between Korokoro and Petone. The long term upgrade for SH2 between Korokoro and Petone overbridges includes the construction of a median barrier on SH2, the closure of Cornish Street to SH2 and the upgrade of the Petone Overbridge.
The Transport Agency's project to upgrade SH2 between Dowse Drive and Petone includes:
- Construction of a grade-separated interchange with a roundabout over SH2 at Dowse Drive with a connection to Hutt Road and Dowse Drive.
- Construction of an overbridge to replace the traffic lights at Korokoro connecting Petone and Korokoro.
- Upgrading the section of SH2 between Korokoro and the Petone overbridges by providing a safety barrier to separate north and southbound lanes.
- Rearranging and improving Petone Railway Station's existing Park and Ride carpark facilities including providing an access bridge over SH2 and upgrade of the footbridge.
- A new service road between Cornish Street and Korokoro providing access to the industrial area.
- An upgrade of the Percy Scenic Reserve access and parking facilities.
These plans and the options considered were developed through a public consultation programme.