The Transport Agency has paid $47.5 million to consultants in the past three financial years.
Figures obtained by Radio New Zealand show the money went to 711 consultants. Almost $10.25 million went to 10 companies.
At the top of that list is Educating NZ, which delivers a road safety programme in schools, followed by R&D Consultants NZ, which monitors long-term road pavement performance.
NZTA says the money paid to consultants is less than 0.5% of the $3 billion spent on transport solutions.