The government is requiring updates to trains that carry potentially explosive crude oil across the country, including Oklahoma.
Tank cars will need stronger walls and lining to help prevent them from rupturing in an accident, like this one that killed 47 people in Canada. The trains will also need a new type of brakes that stops all a trains' cars at the same time.
The new requirements will go into place in phases over the next six years.
Oklahoma has an agreement with railroads that says it won't release information about when trains carrying the oil travels through the state.