• A significant cause of the increased consumption of energy in the transport sector is the increase of transportation by automobiles that have a worse energy intensity. The energy intensity of airplane has improved and in recent years, is better than that of automobiles.

• While the theoretical mileage of owned automobiles deteriorated in the mid 1990s mainly due to the increased weight of automobiles in use, the level has been improving. Actual mileage is also showing an improvement trend.