Last week's deadly Metro North train derailment in the Bronx is prompting nationwide changes.
The Federal Railroad Administration is ordering railroads all over the country to review rules about speed.
The FRA wants railroads to brief employees on the circumstances of the derailment and train them on the importance of speed limits.
The directive also says railroads should remind workers about the importance of communication between crew members, including during long periods of inactivity.
Investigators found the Metro-North train was traveling at 82 m.p.h. in a 30 m.p.h. zone when it derailed last Sunday, killing 4 people and injuring dozens more.
Representatives of the engineer at the helm of the train at the time say he "lost focus."