In March 1987 Upper Hutt welcomed the long-awaited Upper Hutt bypass, which was quickly named as "River Road" to take SH2 away from the long, slow, traffic signal stopped drive through Silverstream, Heretaunga, Trentham, Wallaceville and Upper Hutt along Fergusson Drive, to a new fast route, at state highway speeds, following the Hutt River to Moonshine Rd, then crossing to the east side of the river to connect at Maoribank. The road was one of the last major highway projects in the Wellington region commissioned by the National Roads Board (NRB), which was an arm of the Ministry of Works & Development (MWD). In 1989 these functions would be transferred to a new Crown entity called Transit New Zealand, which would be state highway manager and land transport funder, and the MWD would be reformed into a state-owned enterprise, which would be later split and privatised in 1996. The motivation behind these reforms is a part of this story.
The new road not only saved considerable time for through traffic from the Wairarapa through to Lower Hutt and Wellington, but also better connected the western suburbs of Upper Hutt, and removed a great deal of heavy traffic from Fergusson Drive, where it interacted with pedestrians, cyclists and created safety hazards and generated pollution for the city. Ultimately it opened up new areas for housing west of the river at what is now known as Riverstone Terraces.
However, the road was built at a deliberately low cost. It had sign and traffic signal controlled intersections, rather than grade-separated ones. The Moonshine Road intersection placed immediately north of the bridge was particularly poorly designed (and has since been relegated to having access to/from the highway southbound only).
Despite having a 100km/h limit, the new Moonshine Bridge was built to a 70 km/h design standard, creating an awkwardly tight bend for highway traffic around halfway along the route. It also was not built with any passing lanes, a problem which became clear soon after it was opened, as motorists complained about being stuck behind trucks, but also motorists who would stop along the route to sightsee or park by the river.
The MWD had a solution. It did not have the funding (which at the time was part of the annual budgeting process of the Minister of Finance) to widen the road for passing lanes at the conventional highway lane width standard of 3.5 metres. The road had been built with one 3.5 metre lane in each direction, and with sealed shoulders. So it was decided as a quick fix, to fashion passing lanes between Silverstream and Moonshine Bridge within the pre-existing sealed carriageway, by removing the sealed shoulder so that an additional lane could be marked out. This was done, but had several major problems:
- The lane widths were narrowed to be 3m not 3.5m
- The passing lane taper lengths were shorter than the usual standard
- The speed limit remained the same
- No median barriers, let alone painted median was installed.