Columbia subject headings:
Transportation and state--Europe--Congresses.
Transportation--Cost effectiveness--Congresses.
Harvard subject headings:
Cost effectiveness.
Transportation and state--Europe--Congresses.
Transportation and state--Europe.
Transportation--Cost effectiveness--Congresses.
Transportation--Europe
Transportation--Europe--Planning.
Princeton subject headings:
Transportation and state--Europe--Congresses.
Transportation--Cost effectiveness--Congresses.