Alton Towers has said that "human error" caused the crash in the summer in which five people were seriously injured.
The theme park said staff misunderstood a message to shutdown the Smiler ride, and instead restarted it without taking the proper safety precautions.
Alton Towers said that its investigation found no mechanical or technical issues.
The ride has been closed since the crash on 2 June, but will reopen next year after a number of extra safety features are added.
Sixteen people were injured when an empty carriage collided with theirs, resulting in two women having their legs amputated. Alton Towers has said all 16 people will receive compensation.
"A ride shutdown message was misunderstood by staff at the ride," an Alton Towers spokesperson said.
"This led to a decision to manually restart the ride, overriding the control system without appropriate safety protocols being followed correctly."
Earlier this month, Alton Towers said the impact of the crash on visitor numbers could force it to cut 190 jobs.