Tauranga MP Simon Bridges is quickly ruling out home town favouritism when it comes to road projects, but is keeping the door open on the Hairini underpass as the new Minister of Transport.

Yesterday's parliamentary shake-up saw Simon promoted to Deputy Leader of The House and is the new Associate Minister of Justice and Minister of Transport.

Tauranga MP Simon Bridges says he will not show roading favouritism to the Bay of Plenty.

This is in addition to his previously held portfolios of Energy and Resources, and Associate Minister for Climate Change.

Speaking to SunLive from Wellington, Simon says the Energy and Resources and Transport portfolio's are his two big tasks with infrastructural focus.

But in doing so he mustn't show favouritism to the Bay of Plenty when it comes to roading projects, including the Hairini project.

Previous Transport Minister Gerry Brownlee announced earlier this year that Tauranga ratepayers have been handed a $45m bill for the Turret Road Project.

The $45 million is the remainder of the $100 million Prime Minister John Key promised the government will spend four-laning the Tauranga central corridor. The $55 million Maungatapu underpass is part of that promise.

The New Zealand Transport Agency confirmed $70million of funding for the Hairini Link project earlier this year.

The project will separate Welcome Bay commuter traffic from State Highway 29 by an underpass at the Maungatapu roundabout, a raised roadway down into the Kaitemako Valley and a roundabout and new bridge across the Kaitemako Stream.

It will provide motorists with a direct link from Turret Road at the Hairini causeway to Welcome Bay.

'I think I will have to be careful not to show favouritism to my home area,” says Simon. 'But it's also very true that given I'm the MP for Tauranga I have an empathy and understanding for the need and access in our area.

'I will make sure that the Bay of Plenty is going to get its fair share of infrastructure investment.”

The promotion in terms of portfolios has Simon among a number of ministers who the Prime Minister promoted either to the front bench or further up, to reflect strong performance in recent years and their promise for the future.

Simon says it is humbling to be promoted to the front bench, but isn't taking things for granted with a lot of hard work in front of him to repay the faith the Tauranga voters instilled in him for a third term.

'I'm humbled and really excited by the opportunity the Prime Minister has given me,” he added.

'I feel certain I'm ready for it [the step up]. Whilst it's going to be a challenge, I can do a strong job.”