Citing a "critical" risk to Metro workers, the Federal Transit Administration is ordering immediate safety changes at Metro.

WASHINGTON — Citing a “critical” risk to Metro workers, the Federal Transit Administration is ordering immediate safety changes at Metro.

According to a letter from the FTA to Metro General Manager Paul Wiedefeld, there have been at least four instances just this year where violations of Metro’s worker protection rules have led to trains at full speed passing workers who were not necessarily supposed to be on the tracks.

“Recent incidents on Metrorail are evidence that WMATA has not consistently followed its own [roadway worker protection] requirements and that unsafe practices exist that present substantial risk of death or personal injury to roadway workers,” the letter signed by FTA Associate Administrator Thomas Littleton said.

The letter comes with an unusually strict deadline and threat: without action within five days, the FTA threatens to withhold 25 percent of a key federal funding source for Metro until the new requirements are met.

As a rationale for the threat, the FTA letter points to safety directives over the last two years that have not yet been implemented.

Nineteen of the older required actions are open and past due, 10 are under review by the FTA or have been closed, and three are not yet due.

“Given these recent, very serious incidents, and WMATA’ s delay in implementing the required actions in Safety Directives … I find that unsafe conditions and practices exist that present a substantial risk of death or personal injury to roadway workers at WMA TA,” Littleton said in the letter.

Last year, federal inspectors were nearly struck on the tracks.

In a statement Monday, Metro said it shares the FTA’s concerns.

“We will provide a full and timely response to all of the recommendations in the FTA’s letter,” the emailed statement said.

Metro cites improvements in the Rail Operations Control Center that require extra documentation of work zone protections as well as the system’s pilot program to automatically alert workers and train operators when trains approach a work zone.

The FTA letter requires Metro go further by adding at least one backup method to hold trains outside of a work zone when workers are today only essentially being protected by the radio announcements alerting train operators to their location. The added step could slow riders down when trains are moving through or near work zones in order to keep workers safe.

The FTA is also ordering Metro to clarify all proper communication protocols required for workers to have safe access to the tracks for things such as inspections, and to add more rail controllers to reduce the workload, distraction and potential for miscommunication.

The FTA acknowledges that Metro has made progress on rail controller training and radio communications, but said that ineffective protocols and limited staffing added to distractions for people in key positions is impeding safe operations of the rail system.