The Transport Agency is facing a shortfall of $160 million for the maintenance, operations and renewal of state highways.
In a consultation document, NZTA says it is facing an annual increase of 6% for maintenance, operations and renewals expenditure during the next three years, without any corresponding increase in budget.
It says that amounts to a shortfall of $160 million.
However, the agency says it will not allow the quality of the roads to drop.
Network operations group manager Colin Crampton says savings will be sought through better economies of scale and effective use of resources.
NZTA intends to spend $1.4 billion on highways maintenance, operations and renewal in the next three years.
But Labour transport spokesperson Phil Twyford says there wouldn't be a funding problem if the Government wasn't wasting billions of dollars building low value motorways projects.
He says unless the NZTA can find efficiencies and cost savings through new contracting arrangements and so less work will be done and New Zealand highways will fall into disrepair.
Greens' transport spokesperson Julie Anne Genter says it's more evidence that the Government has mismanaged the transport budget by putting a large part of the money on a few motorway projects which aren't proven to have any economic benefit.
Ms Genter says because of that every other area of the transport budget is suffering.