Tighter environmental rules effective next month in Shanghai are part of the reason for the rise in taxi fares.

The city will enforce National IV emission standards, equivalent to Euro IV, from next month, ahead of a nationwide deadline. The initiative is part of the effort to clean up the air ahead of the Shanghai World Expo which starts next May.

The upgrade in fuel quality will result in a rise in pump prices.

According to Wu Jianrong, vice director of the Shanghai Development and Reform Commission, new fuel prices are still pending approval but will be basically in line with those in Beijing, which introduced National IV standards last year before the Olympic Games.

The National IV upgrade will be in place across the county by the start of 2011 at the latest.

Shanghai will also stop selling cheaper 90-octane gasoline from next month.