11.   With that kind of spacing, a short delay causes immediate backups.

12.   Air traffic controllers say airlines cause much of the problem by scheduling more flights into some airports than can land, causing a backup.

13.   Another truck turned over on the autobahn between Berlin and Nuremberg, causing major backups.

14.   As a precaution, airports along the Adriatic in Bari and Brindisi were closed to commercial traffic, with planes rerouted to Naples, causing huge backups.

15.   Poland imposed extra duties on used cars in March, causing similar backups at the German-Polish border as importers rushed to beat the deadline.

16.   Squeezing in an emergency could cause hourlong backups, and often doctors referred emergency patients from their own jammed waiting rooms to expensive urgent-care centers.

17.   Uprooted trees and overflowing drains forced the closure of several roads, causing long backups in the morning and afternoon rush hours.

18.   The protest caused traffic backups which paralysed the rest of the central district.