Today, public submissions - which should prove to be a far more colourful part of the hearing - begin.
Yesterday's evidence related exclusively to the harbour arterial route, with commissioners questioning witnesses on whether the project was really necessary, or merely a "luxury".
They also expressed concern a possible 20-year time-frame for some parts of the route might leave landowners, whose land could be acquired under the Public Works Act, up in the air for that length of time.
Council planner Jane Macleod began the day, continuing her evidence from Tuesday.
Asked by Mr Matthews how such a large project would fit in with the 2011 Rugby World Cup timetable, given the stadium could not be built without the road in place, Ms Macleod said it would be done in stages.
The north end, running past the stadium, would be built first.
Some businesses in Anzac Ave were expected to suffer from lower passing custom once the road was split by the arterial route at Frederick St, especially the Mobil service station and Automotive Solutions.
While the council would provide improved signage and access via other routes if possible, Ms Macleod said the businesses would experience decreased custom.
Counsel Michael Garbett, presenting the council's argument for the notice of requirement, said the land needed by the council would have to be purchased under agreement, or acquired under the Public Works Act, and full compensation paid.
The benefits of the arterial route would be a freer-flowing route from the south of the city to Port Chalmers, safer roads, fewer heavy vehicles in the inner city, and "permeability" between the city and the harbour side.
On the other side of the ledger, there would be direct effects on property owners, construction effects, noise, and an increase in traffic on roads such as Frederick St.
But, overall, the benefits outweighed those effects.
"This is a large roading project that will inevitably have some effects," Mr Garbett said.
Council transportation planning manager Don Hill said the new route would solve traffic problems at the Jetty St off-ramp, and the St Andrew St rail crossing.
Cheaper vehicles had resulted in "very, very rapid growth" in traffic volume.
Freight transport was also expected to grow, with only some being transported by rail.
There would be a 15m to 20m cycle and pedestrian tunnel under the "gyratory", or large elevated roundabout, over the railway line to Frederick St, which would close Anzac Ave at that point.
The gyratory would be raised on a mound of earth rather than concrete piles because it was a cheaper option.
Dealing with submissions, Mr Hill said many linked the need for the arterial route with the stadium, but "this is incorrect".
The arterial project predated the stadium.
"This arterial [route] will cater for the future needs of the city and the wider region. The arterial is considered necessary whether or not the stadium proceeds."
Mr Lumsden asked if it was a luxury to have State Highway 1 and the new arterial route.
Mr Hill responded that the route addressed issues such as the railway crossing and traffic issues around the university campus.
MWH transportation engineer Jeremy Byfield considered safety in his evidence, noting there had been 92 recorded crashes between Thomas Burns St and Ravensbourne Rd in the past five years, with 40 resulting in injury.
More than half occurred at intersections, many of which would be closed or significantly altered if the project went ahead.
While there were benefits from the changes, there were also drawbacks, including a greater pressure on some intersections.
These needed to be addressed as "there are clearly a number of specific locations that are likely to see a reduction in safety".
The gyratory would be controlled by traffic lights and would be a safe intersection if properly designed.
The commissioners questioned Mr Byfield closely on the apparently limited benefit of the new road in terms of safety.
He replied the arterial route was not a safety-driven project.
Urban designer Janet Reeves said the severing of Anzac Ave would remove the experience of arriving in the city by the "ceremonial route" of the avenue, which was "something special" and important to protect.
There was discussion about the the history of the avenue, which was built for the South Seas International Exhibition, held in 1925-26.
However, Anzac Ave would be enhanced by being quieter, Ms Reeves said.
She recommended pedestrians be catered for on the new route.
Acoustics consultant Rob Hay told the committee noise levels from the gyratory would be minor.
Julie McMinn, a planning consultant for Opus International Consultants, was the last of the council's witnesses.
Her report considered the proposal, its environmental effects, submissions and Ms Macleod's report.
Ms McMinn said she believed the proposed route met requirements and that the adverse effects were outweighed by the project's benefits.
Mr Matthews raised the issue of the property owners having to wait up to 20 years before their properties were used, something he described as "problematic".
He also said it was "quite material" to the hearing if those making submissions had not been notified.
