Baldock said the $400m could be funded from the regional council's $1.75 billion stake in the Port of Tauranga - expected to return $62m in dividends this year.
Another $180m could come from a regional fuel tax of 10c a litre over 10 years.
''And we could ask ratepayers to contribute through a targeted rate,'' he said.
Baldock put the idea to last week's public hearings on the draft Regional Land Transport Plan, saying there was a lack of focus and urgency to finish the four-lane/grade separated ring road around Tauranga.
The ring road plan was originally designed to ensure traffic could travel at no less than 80km/h, with connections to the Tauranga Eastern Link to Paengaroa and the Tauranga Northern Link.
''Completion of the ring road was vital to the social and economic health of Tauranga. We often talk of not becoming like Auckland, yet every year we slide towards becoming more and more like them.''
Baldock said the big question was where the $2 billion would come from in order to avoid the traffic gridlock that had enveloped Auckland. Relying on funding from traditional central government sources meant Tauranga would never catch up.
He said it was "entirely reasonable'' to consider a $300m to $400m contribution from the regional council.
''If we can approach central government with a local contribution of half a billion dollars, perhaps we will be taken more seriously.''
Baldock argued that the continued success of the port depended on efficient freight movements. It was therefore important that the regional council - the port's majority shareholder - future proofed the efficiency and profitability of the port.
''Failure could see the value of its shares reduce,'' he said.
''If this city is left to become more and more gridlocked, the effect will impact on everyone across the region.''
Baldock said big-picture issues had remained pretty much the same today as they were 15 years ago. What had changed was how the costs to finish the city's strategic roading network had risen from $500m to $600m to today's bill of closer to $2 billion.
Leeder responded to the Bay of Plenty Times that the lion's share of the council's port dividends were used to subsidise rates. If $300m to $400m of dividends were diverted over 10 years to roading projects, the shortfall would have to be met by ratepayers.
He said the dividends paid to the council by Quayside Holdings helped fund a whole lot of council activities. Without this money, the general rate levied by the council would more than double.
Leeder said it would have been more appropriate for Baldock to have channelled his request through the regional council's draft Long Term Plan.
If subsidies had been removed from the regional rate component of this year's council's rates, it would have cost each Tauranga ratepayer an additional $216.
Proposed regional council rates this year for Tauranga totalled $380 made up of $216 for the regional rate (up $21), $144 for the public transport rate (up $82) and $20 for civil defence (new targeted rate).
Roadworks needed to make Tauranga's ring road function at full efficiency included four-laning Maungatapu Bridge, grade separating intersections along Hewletts Rd and grade separating Takitimu Drive's intersection with Elizabeth St.
Tauranga's ring road
- The Harbour Bridge and approaches.
- Takitimu Drive to SH29 via Route K.
- SH29 to Baypark
- Baypark to Hewletts Rd via Maunganui Rd
- Hewletts Rd to the Harbour Bridge causeway
