Columbia subject headings:
Metropolitan areas--Europe--Planning--Congresses.
Traffic congestion--Environmental aspects--Europe--Congresses.
Traffic congestion--Europe--Congresses.
Traffic engineering--Europe--Congresses.
Transportation--Europe--Congresses.
Urban transportation--Europe--Congresses.
Harvard subject headings:
Princeton subject headings:
Metropolitan areas--Europe--Congresses.
Traffic engineering--Europe--Congresses.
Urban transportation--Europe--Congresses.