The emergency order was published in the Federal Register and took effect Oct. 27.

Violators of this prohibition are now subject to civil penalties and removal from safety-sensitive service.

"Operating freight and passenger trains, and maintaining track and signals requires the full and undivided attention of those charged with carrying out such responsibilities," said FRA Administrator Joseph Boardman.

The FRA's emergency order came after the National Transportation Safety Board said on Oct. 1 that the Metrolink engineer involved in a Sept. 12 train accident in Los Angeles had sent a cell phone text message 22 seconds before his commuter train crashed head-on into a freight train, killing 25, including the engineer.

Cell-phone records of engineer Robert Sanchez show he sent a text message after receiving one about a minute and 20 seconds before the crash, the NTSB said.

Records obtained from Sanchez's cell phone provider also showed that he sent 24 text messages and received 21 messages over a two-hour period during his morning shift, the NTSB said. During his afternoon shift, he received seven and sent five messages, the NTSB said.

The FRA's Boardman also said:

"The bottom line is railroad operating employees cannot focus on their critical safety functions while engaging in phone conversations, texting or any other form of unessential electronic communication, often in violation of railroad operating rules."

To read the emergency order, click below: http://www.fra.dot.gov/downloads/PubAffairs/EmergencyOrder26.pdf.

To view the FRA's Electronic and Electrical Device Flowchart, click here.