Bangkok was ranked as having the eighth worst traffic based on research by the motor-oil company Castrol compiled in the Castrol MAGNATEC STOP-START Index (See here)
The index uses GPS data and includes traffic conditions and number of annual start and stops per car to determine how traffic affects journey times. More than 18,000 stop-starts is defined as severe traffic for a city. More stop-starts also increases engine wear. The index also looks at the amount of time cars spend idling. Some of the worst idling times were recorded in Thailand. Around 36% of an average driver’s travel time in Bangkok was spent with the motor of the car idling.