Longest traffic jam (number of vehicles)
18,000,000 total number
Germany ()

A traffic jam of 18 million cars crawling bumper-to-bumper was reported on the East–West German border on 12 April 1990. When the Berlin Wall fell on 9 November 1989, thousands of Germans streamed across the borders that had divided East from West for decades, attracted by the prospect of seeing relatives and rediscovering parts of their country that had been out of bounds for so long. Sheer weight of vehicle numbers led to the monumental traffic jams of 12 April 1990.

While it was the overwhelming number of vehicles that led to these huge traffic jams, scientists have recently come up with innovative theories to explain this frustrating phenomenon. A study by Dr Takashi Nagatini, published in the journal Physical Review E in April 2000, blames erratic driving. By slowing down unexpectedly, drivers on busy motorways send "waves" of congestion out behind them as other drivers are forced to brake, causing jams even though there is no physical obstruction in the road. Whatever the cause, traffic jams are not a strictly modern phenomenon: Julius Caesar banned carts and chariots from Rome during daytime in the first century BC, and congestion was so bad in European cities by the 17th century that one-way systems and no-parking areas were created.