Columbia subject headings:
Highway planning--OECD countries.
Roads--Maintenance and repair--Evaluation.
Roads--OECD countries.
Transportation and state--OECD countries.
Harvard subject headings:
Highway planning--OECD countries.
Roads--Maintenance and repair--Evaluation.
Roads--OECD countries.
Transportation and state--OECD countries.
Princeton subject headings:
Highway planning.
Roads--Maintenance and repair--Evaluation.
Transportation and state.