Three out of four road accidents during the Songkran festival involved motorcycles, with drunk driving the biggest single cause of crashes, according to the Disaster Prevention and Mitigation Department.

A total of 321 people were killed and 3,040 injured in 2,828 road accidents nationwide during the seven dangerous days (April 11-17) of the Songkran holiday.

The number of accidents was down 9.62% on 2012 when there were 3,129 crashes. The number of injuries was also down, 8.43%, but the death toll was one more than for the same seven-day period in 2012.

Deputy Interior Minister Pol Lt Gen Chatt Kuldiloke said drunk drinking was the main cause of accidents, with alcohol involved in 39.11%, followed by speeding at 23.59%.

He said 78.11% of accidents involved motorcycles, and 21% of the deaths and injuries during the seven days were attributed to motorcyclists not wearing crash helmets.

Public Health Minister Pradit Sintawanarong said motorcycles are the most popular form of transport in Thailand, with 19 million bikes registered with the Department of Land Transport at the end of 2012.

Motorcycles accounted for 58.6% of the total 32.4 million vehicle registrations, followed by personal vehicles not exceeding seven seats at 36%.