SRT Governor Prapas Jongsanguan said most accidents occurred in the north. The latest one was last night in Phrae province.
He said most investigations indicated the cause of the accidents was aging tracks which needed immediate maintenance or replacement.
The original plan was to close the 300-kilometre stretch of the railway from Sila At Staion in Uttaradit to Chiang Mai from November to August next year.
However, Gov Prapas said since recently accidents have happened often, the SRT decided to begin repairs sooner, starting next week from September 16 to the end of October.
The SRT chief said some 2,000 passengers will be inconvenienced daily. Five roundtrip trains usually operate from Sila At to Chiang Mai daily. Passengers will be provided alternate connections from the Transport Company -- free air-conditioned buses. Those not wishing to travel during rail maintenance are welcome to refund their tickets, he said.
Mr Prapas said he believed the railroad renovation would help lessen accidents and SRT is to lower the number of accidents to zero in the future.
According to Mr Prapas, a budget of Bt2.8 billion was set to replace the tracks from Sila At to Chiang Mai stations. This part of the budget was part of a nationwide repair budget of over Bt70 billion approved by the previous government.