The Welcome Bay underpass comes a step closer with the announcement another $3.1million will be spent on the project.
The money will pay for an investigation of route options including widening 15th Avenue, Turret Road and the Hairini Bridge to improve travel time to and from the city. Money will also be spent on investigating the use of under passes and over passes at the roundabout system at Maungatapu and Hairini.

The Hairini funding is part of the $495 million that New Zealand Transport Agency recently announced will be spent on Bay of Plenty roading.
The Hairini money will allow planning to get to the point of developing a preferred option.
There will be an in depth investigation of route options, public consultation and then the development of a preferred option.
When the preferred option is established, a Notice of Requirement will be lodged to gain a designation for the preferred route. At that point the $3.1 million will be spent.
More money will then be sought to take the project through detailed engineering design, resource consents and the purchase of properties needed for the project.
When that is completed the project will be ready to take to tender and a fourth round of funding will be applied for construction of the $134 million Hairini Link project.
It will be six years before any construction happens. The project will not be completed for eight years.
NZTA regional director Harry Wilson says the funding recently announced is the second round of funding for Hairini Link.
'As the larger project will not be completed straight away, advanced works are already being planned that aim to ease traffic congestion and improve public transport, walking and cycling."

An open day providing details of those advanced works is scheduled for October this year, with the date expected to be known later this week.
Meanwhile the Northern Arterial route out of the city will have $10.6 million spent on a secondary investigation expected to begin in November.
It will focus on a 6.8km section of State Highway Two from the Loop Road intersection north of Te Puna to Route K in Tauranga City.
The secondary investigation is expected to take about two years to complete. Its objectives are to review the design and scope of the project, identifying options and changes and to confirm the appropriateness of the longstanding designation. Construction of the northern arterial is not included in the NZTA's 10 year forecast, which means nothing will happen there for at least 15 years.