In January 2005, an accident in Graniteville, South Carolina, which killed nine people and resulted in the release of toxic chlorine gas, occurred when a train was erroneously diverted off a mainline track due to an improperly lined switch, then collided with a parked train.

In an effort to reduce such human-error-driven accidents, which have been on the rise, the U.S. Department of Transportation has issued a regulation that places greater accountability on both railroad management and employees for complying with basic operating rules, according to a release from the agency.

The rule establishes that  "relatively simple errors such as improperly lined track switches, shoving rail cars without a person in front to monitor for clear track ahead, and leaving rail cars in a position that obstruct or foul an active track may now result in a violation of federal rail safety regulations," says the release [1]. In the past, these infractions were not treated as safety violations.