A multi-million dollar upgrade on the Kaimai Tunnel could be a game changer for freight transport in the Bay of Plenty.
Investigations are underway to assess the scope of work needed to upgrade the rail track and tunnel floor for the first time since it opened 36 years ago.
Five million dollars had been committed next year for heavy maintenance.
A further $8 million will be allocated in 2017 for repairs to the concrete slab floor and drainage.
Work will take place over the next five to ten years to upgrade the 8.9 kilometre tunnel.
Minister of Transport Simon Bridges and Minister of State Owned Enterprises Todd McClay visited the tunnel today with Kiwirail staff.
Mr Bridges said Early estimates indicate the total cost of the improvements could be in the order of $40-50 million.
"The purpose of the visit is to understand our investment in this critical link, which is vital to improving freight efficiency and productivity," Mr Bridges said.
Mr McClay said work will future proof the busy transport route that links the Bay of Plenty to the Waikato, Auckland and beyond.
"This is a substantial piece of work to improve and refurbish the track and tunnel floor, and to ensure it is prepared for future increased demand," Mr McClay said.
"This is a considerable investment that demonstrates the Government's ongoing commitment to improving trade links between regional New Zealand and its urban centres."
Future financial commitments beyond 2017 will be determined as part of the secondary investigation phase.