Police have blocked main roads in Tokyo during rush hour in an elaborate earthquake drill.
It was the first attempt by Japan to simulate the gridlock that would occur after a major disaster.
Drills are held across Japan every year on 1 September, the anniversary of a magnitude 8.3 earthquake in Tokyo in 1923.
The BBC reports this year has been taken even more seriously than usual because of the earthquake and tsunami that struck the north-east of the country on 11 March.
Traffic was stopped for 9am on Thursday for 10 minutes at 100 points in Tokyo. Jams quickly built up.
The aim was to practise how emergency vehicles would get through the gridlock feared after an earthquake centred on the city.
Schoolchildren across Japan take part in frequent earthquake drills. This was the first time that traffic has been halted.
