The New Zealand Transport Agency wants a designation change from the Dunedin City Council to allow for a second stage of safety improvements to upgrade SH1 - the $20 million first stage of roadworks on the lower stretch of the valley route is already under way and scheduled for completion next year.
A public hearing to deliberate the agency's notice of requirement proposal, to outline one of the most expensive and significant city transport projects in recent times, began yesterday.
Agency counsel Kerry Smith said a total of 131 road crashes, which include fatalities, had been recorded during a 10-year period on the troublesome stretch of state highway.
The road crash statistics were backed by evidence from Opus International Consultants transportation manager David Eaton, who said the existing highway was no longer fit "for purpose" and was deficient in some areas of national safety standards expected for an arterial road.
About 34 houses would be removed from along Caversham Valley Rd, between Barnes Dr and Lookout Point, to make way for the SH1 construction project to widen Dunedin's main southern route and incorporate several other transport features.
Agency projects team manager Simon Underwood said the primary objectives behind the proposed improvements were to better address safety and network travel efficiencies.
He told a hearings panel of chairman Colin Weatherall, Kate Wilson and David Benson-Pope the objectives would be achieved by "improved connectivity" across SH1 by building an overbridge connecting Riselaw and Mornington Rds.
Improved side road intersections to and from Caversham Valley Rd and better provision for pedestrians and cyclists, along and across the highway corridor, were also primary considerations, he said.
The agency wants to install a barrier to separate opposing traffic flows along Caversham Valley Rd - the only section of the southern arterial route between Dunedin and Mosgiel not to have a central median - and widen existing lanes by 1.8m road shoulders on either side.
The proposed overbridge would not be a unique addition to Dunedin's transport network, Mr Underwood said.
"In many ways, there will be similarities between these improvements and the upper section of Stuart St; that there is a four-lane carriageway with median, houses on one side, footpaths both sides [and] a bridge at the crest providing linkage to a cross route," he told the panel.
The DCC and the New Zealand Fire Service have "expressed strong views in favour of a [Lookout Point over] bridge for reasons of safety and community connectivity", Mr Underwood said.
The agency had amended its initial proposal and would no longer create a cul-de-sac at the top of South Rd prohibiting access to SH1, he said.
The proposal change addressed access concerns raised in submissions from some South Rd residents and also a public transport issue raised by the Otago Regional Council.
The amended proposal would ensure an ORC public transport service for Calton Hill, via a bus route loop, would remain, albeit in a different direction, he said.
Traffic movements of about 26,000 vehicles a day using SH1 through the Caversham Valley meant the south city route was very busy.
"There is only one road which I'm aware of in Dunedin - a short stretch along Andersons Bay Rd - which is busier. In the context of the South Island, outside of Christchurch, this is one of the busiest roads we have," Mr Underwood said.
Hearings commissioner David Benson-Pope questioned whether congestion problems on the route could be improved by an "integrated solution" at the traffic-light controlled intersection of Barnes Dr.
The agency had investigated the option of building another overbridge to remove the traffic lights, but the additional cost of more than $15 million was not justified, Mr Underwood said.
"[It is] not operating at capacity now and [the existing situation] will be improved by the addition of left-hand turning lanes at the intersection lights," he said.
The hearing continues today.
