Silverdale Village and the Silverdale Business Park are severed by the Hibiscus Coast Highway (HCH), the primary arterial which links the Whangaparaoa Peninsula and Orewa with the Northern Motorway. Silverdale Street is the Silverdale Village main street and connects the HCH with Wainui Road and Millwater Parkway. Tavern Road serves the Silverdale Business Park and connects the HCH opposite Silverdale Street with East Coast Road. There are relatively steep downgrades on the HBC approaches to the intersection and traffic speeds are relatively high on the highway. For safety reasons traffic is not permitted to cross the HCH between Silverdale Street and Tavern Road. Also traffic is not permitted to turn right into HCH from either road causing community severance, increased trip lengths and limitations on accessability which limit local economic growth.
The introduction of traffic signal control of the intersection would significantly improve the accessibility of the Silverdale Village and the Silverdale Business Park by accommodating currently banned traffic movements. The traffic assessment estimated the volumes of the traffic movements currently unable to take place, then calculated travel time and vehicle operating benefits for these movements using a Sidra model. The resulting net present value of the evening peak period benefits across the local network was $1,543,000 compared with the previously estimated cost for installing traffic signals of $1,300,000. This indicated that a positive return on the investment could be achieved.
Based on the findings it was recommended that traffic signal installation at the HCH/ Silverdale Street/ Tavern Road intersection be explored further due to the much improved accessibility of both the Silverdale Business Park and Silverdale Village, and the potential wider network benefits.