NTSB -- NTSB ISSUES URGENT SAFETY RECOMMENDATIONS IN WAKE OF RECENT FATAL WASHINGTON, D.C. METRORAIL COLLISION TO ADDRESS NEED FOR REDUNDANT SAFETY IN RAIL TRANSIT SYSTEMS

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NTSB PRESS RELEASE

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National Transportation Safety Board

Washington, DC 20594

FOR IMMEDIATE RELEASE: July 13, 2009

SB-09-36

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NTSB ISSUES URGENT SAFETY RECOMMENDATIONS IN WAKE OF RECENT

FATAL WASHINGTON, D.C. METRORAIL COLLISION TO ADDRESS NEED

FOR REDUNDANT SAFETY IN RAIL TRANSIT SYSTEMS

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The National Transportation Safety Board today issued an

urgent safety recommendation to the Washington Metropolitan

Area Transit Authority (WMATA) calling for enhanced safety

redundancy of its train control system.

A recent accident on the Metrorail's Red Line between the

Fort Totten and Takoma stations has shown that WMATA's train

control system is susceptible to a single point failure

because it did not fail safe and stop a train when detection

of a preceding train was lost. The urgent safety

recommendation issued today calls for WMATA to evaluate

track occupancy data on a real-time basis in order to detect

losses in track occupancy and automatically generate alerts

to prompt such actions as immediately stopping train

movements or implementing appropriate speed restrictions to

prevent collisions.

The Safety Board made a second urgent recommendation to the

Federal Transit Administration (FTA) urging the agency to

advise all rail transit operators with train control systems

capable of monitoring train movements to evaluate their

systems for adequate safety redundancy.

Although the NTSB's investigation is not yet complete and no

determination of probable cause has been reached,

investigators have concerns regarding the safety redundancy

of WMATA's train control system.

"While the NTSB is still in the very early stages of its

investigation into this tragic accident here in our nation's

capital," said Acting Chairman Mark V. Rosenker, "we have

concerns about the failure of WMATA's train control system

to prevent this collision." Rosenker continued, "By calling

upon WMATA to take swift action to upgrade the safety

redundancy of its system and by urging FTA to alert other

transit agencies of the hazards of single point failures

such as the one experienced by WMATA, we hope to prevent

something similar from happening again."

In accordance with NTSB protocol, the letters were issued to

the heads of both agencies with a request for a response

from each organization within 30 days, addressing the

actions taken or planned in response to the Board's

recommendation.

The safety recommendation letter to WMATA may be found here:

http://www.ntsb.gov/recs/letters/2009/R09_6.pdf

The safety recommendation letter to the FTA may be found

here: http://www.ntsb.gov/recs/letters/2009/R09_7.pdf

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NTSB Media Contact: Bridget Serchak

202-314-6100

Bridget.serchak@xxxxxxxx

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