Economic losses caused by traffic jams throughout Japan total approximately 12 trillion yen a year, some 95,000 yen per capita, the Land, Infrastructure and Transport Ministry said Saturday.

According to the ministry's first attempt to determine the effect of traffic jams in yen terms, Tokyo suffered the highest annual loss of Japan's 47 prefectures at 1.55 trillion yen, followed by Osaka with 693 billion yen and Aichi with 612.9 billion yen.

Losses calculated for every 1 km stretch of road stood at 67.1 million yen in Tokyo, some 38.94 million yen in Osaka and 22.61 million yen in Okinawa.

Tottori suffered the lowest losses per year, some 52.5 billion yen, followed by Fukui with 71.3 billion yen. Seven prefectures had losses of less than 100 billion yen, according to the ministry.

By loss for each 1 km of road, Iwate was least affected, with 4.75 million yen, followed by Shimane with 5.08 million yen.

Hokkaido ranked seventh in total annual losses with 479.2 billion yen, but per 1 km of road it only lost 5.58 million yen, placing it 43rd among the 47 prefectures.

The ministry calculated losses based on speed differentials between vehicles stuck in traffic and those not held up, the number of vehicles on roads, the distances driven, average number of passengers and average wage per hour.

The results of the survey will be released via the Internet, showing congestion levels and economic losses from heavy traffic at certain points on Japanese roads.

The data will be used as a guideline when the ministry sets targets for the construction of new roads and explains the need to build more roads. Officials from the ministry said the figures will help the ministry improve accountability for road construction projects.

A ministry official said the losses calculated per 1 km of road better reflect actual traffic jam conditions.