NEW YORK STATE -- Following the Metro-North train derailment, federal authorities are calling for some changes to the rails signal system.
The MTA has until Tuesday to identify all the spots on its lines where there is a 20 mile per hour speed variation.
Federal authorities are also demanding extra operators on lines where there are major speed changes.
This is to make sure train crews don't exceed speed limits.
MTA is on board with the order.
They're also examining other steps to improve safety following the deadly crash which killed four passengers.