Amtrak officials say lights and crossing arms are not required on private property where the train slammed into a truck in Contra Costa County near Discovery Bay.
The train was carrying 204 passengers from Oakland to Bakersfield. Thirty-nine passengers who suffered minor injuries on the train have been released from the hospital.
The driver of the truck and the passenger, along with the train conductor, were not injured.
The train did not derail during the crash and arrived in Bakersfield at 1 a.m. Saturday.