NTSB/RAB-08/01 

E PLURIBUS UNUM

NATIONAL TRA SPORTATIO

N

B OARD

SAFE T Y

N

 

National Transportation Safety Board 

Washington, D.C. 20594 

Railroad Accident Brief

Accident No.: DCA-06-FR-005 

Transit System: Washington Metropolitan Area Transit Authority Metrorail System 

Train: Metrorail Red Line train 

Location Near Dupont Circle Metrorail station, Washington, D.C. 

Date: May 14, 2006 

Time: 10:16 a.m.1

Fatalities: 1 

Type of Accident: Train strikes wayside worker 

Synopsis 

About 10:16 a.m. on Sunday, May 14, 2006, a southbound Washington Metropolitan 

Area Transit Authority (WMATA) Metrorail Red Line subway train struck and killed a Metrorail 

employee as the train was about to enter the Dupont Circle station in Washington, D.C. The 

employee was an automatic train control system mechanic who had been working with two other 

mechanics at the interlocking2 just north of the Dupont Circle station. All three mechanics had 

moved between the two main tracks north of the interlocking in order to stay clear of a 

northbound train that was leaving the station. As the southbound accident train was arriving, the 

other two mechanics remained in the clear between the two trains as they passed and were not 

injured. According to signal system data logs, the southbound train was moving about 40 mph as 

it traveled past the interlocking. 

Events Preceding Accident 

About 6:00 a.m. on May 14, 2006, train controllers working the Red Line console at 

WMATA’s Metrorail Operations Control Center3

 noticed an anomaly with the track circuit4 at 

the interlocking just north of the Dupont Circle station. The controllers notified the Maintenance 

 1

 All times in this brief are eastern daylight time. 

2

 The Metrorail system uses double main tracks designated track 1 and track 2. On this section of the Red Line, 

southbound trains (toward downtown Washington, D.C.) typically use track 1, and northbound trains use track 2. 

The interlocking is a crossover track that allows trains, when necessary, to move from one main track to the other. 

3

 The Operations Control Center coordinates and dispatches all train movements on the Metrorail system. 

4

 The track circuit detects the presence of trains and the positions of switches in order to provide for safe train 

operation. The Metrorail system operates under an automatic train control system that was designed to allow for 

fully automated train operations requiring very little direct involvement from train operators. 
 

2

Operations Center, which dispatched an automatic train control system mechanic (referred to in 

this brief as the “first mechanic”) to Dupont Circle to troubleshoot the system. After reaching the 

station, the mechanic took readings of the electronic equipment in the train control room and 

then asked for and received permission from the control center to go wayside in the tunnel to 

make a visual inspection of the interlocking. (Trains were not running at that time because 

weekend Metrorail service did not begin until 7:00 a.m.) 

About 7:00 a.m., the mechanic reported to the control center that he was clear of the 

tracks and that the problem with the track circuit had apparently cleared itself. Shortly thereafter, 

intermittent problems with the track circuit were again reported. Another automatic train control 

system mechanic (referred to in this brief as the “senior mechanic,” who was struck and killed) 

on duty at Metrorail’s Brentwood Yard radioed the first mechanic, telling him that he (the senior 

mechanic) and another mechanic (referred to in this brief as the “second mechanic”) were on 

their way to assist with the troubleshooting. The first mechanic then returned to the train control 

room, where he was soon joined by a maintenance helper who had come to help. 

The senior mechanic and the second mechanic arrived at the Dupont Circle station about 

9:00 a.m., at which time the senior mechanic assumed the lead in directing the work of the crew. 

Oscilloscope readings showed a slight deviation from normal, so the crew decided to make a 

second wayside inspection. The maintenance helper stayed behind in the control room as the 

three mechanics entered the tunnel to examine the interlocking. 

Before beginning the work, the second mechanic asked the control center for permission 

to go wayside to conduct an inspection. The control center controller granted permission and 

then made a radio broadcast to all train operators on the Red Line that workers were wayside 

near the Dupont Circle station. No subsequent radio broadcasts were made regarding the work. 

Metrorail rules for safety while working on the right-of-way are provided in the 

Metrorail Safety Rules and Procedures Handbook. Rule 4.180b stated: 

Prior to entering the track area, contact OCC [the Operations Control Center] for 

mainline access..., indicating the work area and the purpose of the work. If 

required, a request shall be made for OCC... to make periodic radio 

announcements to Train Operators. 

A related rule, Rule 4.180.1, stated: 

OCC shall make periodic (20-minute) radio announcements to inform Train 

Operators of those locations at which... maintenance actions are being performed 

within the dynamic outline[5

] of a train. These announcements shall be made as 

 5 Dynamic outline, or dynamic envelope, refers to the total area occupied by a moving train. It not only 

incorporates the physical dimensions of the equipment but also accounts for suspension travel, overhang on curves, 

or lateral motion along the track. 
 

3

deemed necessary and as requested by the maintenance personnel performing the 

work. 

The workers did not request that a speed restriction be placed on trains passing through 

the area even though Metrorail right-of-way procedures allowed employees to request speed 

restrictions when necessary for personal safety or for safe passage of trains. Automatic train 

control maintenance supervisors told the National Transportation Safety Board that the control 

center discouraged such restrictions because of their effect on train schedules. 

The workers turned on the overhead lights at the site of the interlocking, then went 

wayside. The first mechanic said he had been the lookout while the more experienced mechanics 

had conducted the inspection. 

The Metrorail Safety Rules and Procedures Handbook, Rule 4.180h, stated: 

When working at a stationary location, ensure that one person is designated to be 

the lookout for passing vehicles and to monitor the appropriate radio frequency. 

The procedures did not include a method to ensure that all members of a work crew were 

made aware of approaching trains or that all workers were in the clear before those trains arrived. 

During the visual inspection of the interlocking, the crew found that some 

C-bonds6

 were missing but found nothing else that could be associated with the reported track 

circuit problem. All three employees then returned to the train control room, which was upstairs, 

to find shunt straps to replace the missing C-bonds if it became necessary. About 9:45 a.m., the 

first and second mechanics went back downstairs while the senior mechanic and the maintenance 

helper remained in the train control room. The senior mechanic adjusted the output to the track 

circuit relay, after which the circuit appeared to function normally. With the problem apparently 

resolved, the crew decided to make a full adjustment of the track circuit before departing the 

station. 

Adjusting the track circuit required that the two wayside mechanics place shunts7

 at 

various locations while the senior mechanic made final adjustments in the train control room. 

Again the first mechanic was the lookout while the second mechanic placed the shunts. As the 

work was underway, trains continued to run, which required the two employees working wayside 

to occasionally clear the work area for passing trains. They later said that they had not discussed 

in advance where they would go to clear for trains but that they had either cleared to the opposite 

 6 C-bonds are copper wires that bridge a rail joint to provide electrical continuity from one rail section to the 

next. 

7

 A shunt is used to form an electrical bridge to simulate the presence of a train in the circuit. 
 

4

track or crossed the track and climbed over the third rail8

 onto one of the safety walkways along 

either side of the tunnel. 

The Metrorail Safety Rules and Procedures Handbook, Rule 4.181, stated: 

Before permitting employees to be on the track, the person in charge of a work 

crew shall have an understanding with all crew members as to where each person 

will go when it is necessary to clear the track for vehicle movement. All crew 

members should clear on the same side of the track. 

The leader of the Dupont Circle work crew (the senior mechanic) did not conduct a job 

briefing before starting the wayside work or when the number of workers or the nature of the 

work changed. Such briefings were not required by the rules and procedures handbook. 

Accident Sequence 

After completing the track circuit adjustments, the senior mechanic asked that a shunt be 

placed on the problem track circuit to verify that it was operational and could detect a train 

occupying the circuit. When the shunt failed to indicate the presence of a train, the senior 

mechanic went wayside to discuss the location of the shunt with the other two mechanics. (The 

maintenance helper remained in the train control room.) During this discussion, a northbound 

train approached the Dupont Circle station platform on track 2. The second mechanic said he 

recalled having called out to announce to the other two workers that a train was coming into the 

station. Both the first and second mechanics said that as the northbound train continued into the 

station, they had felt an increase in air pressure in the tunnel, which they associated with the 

approach of a southbound train on track 1. 

The second mechanic said that he had called out again to announce that trains were on 

both tracks and that the first mechanic had repeated back the message. As the northbound train 

made its station stop, all three workers started walking to the area between the two main tracks 

north of the interlocking. The second mechanic took a position adjacent to a metal rack that 

secured cables descending from the tunnel ceiling to the floor. The first mechanic said that he 

walked north past the second mechanic and onto a concrete safety walk between the two tracks.9

 

A passenger, who had been on the station platform awaiting the arrival of the southbound 

train on track 1, reported having seen the three workers prepare for the departure of the 

northbound train by moving between the tracks. The witness stated that all three workers had 

appeared to be standing with their backs to track 1. The two mechanics stated, and video 

evidence and eyewitness statements confirmed, that the senior mechanic had moved to an open 

area between the tracks adjacent to the crossover. Video evidence also revealed that, at this 

 8

 A third rail, running along the outside of the two main tracks, provides about 750 volts of electricity to power 

the trains. 

9

 The two main tracks at the accident site are spaced at 14 feet on center, and the dynamic width of a Metrorail 

car is 10 feet 11 1/4 inches. Thus, the clearance between passing trains at this location is 3 feet 3/4 inch. 
 

5

location, the senior mechanic was within the dynamic envelope of a train moving along track 1. 

(See figure 1.) 

The operator of the northbound train said that she did not recall having heard any radio 

announcements regarding wayside workers near Dupont Circle but that she did see three workers 

at the other end of the station as her train pulled alongside the passenger platform. She said that 

when her train had serviced the station and was ready to depart, she signaled the crew by 

sounding the train horn. She said she received the all clear flashlight signal from the worker who 

appeared to be standing adjacent to track 1 and closest to the station (this was the senior 

mechanic). She said the other two workers appeared to have walked onto the safety walkway 

between the two tracks. 

Figure 1. Approximate positions of the first mechanic (1), the second mechanic (2), and 

the senior mechanic (S) as the northbound train was leaving the Dupont Circle station 

and the southbound accident train was arriving. 

The northbound train operator said that as her train departed the station she continued to 

look toward the nearest worker (the senior mechanic) until she had passed the work location. She 

said she then looked up and saw the headlights of an approaching southbound train on track 1. 

The operator of the striking southbound train said that he remembered hearing an earlier 

announcement about wayside workers, but that he did not recall any details of the announcement. 

He said that as his train approached the Dupont Circle station, he saw the headlights of the 

northbound train and dimmed his train’s lights. He said that as the two trains passed, he heard a 

loud “boom” followed by a flash of light on the left side of the train. The train brakes applied 
 

6

automatically, at which time, the operator said, he pressed the emergency stop button. He then 

recharged the train air line and moved the train ahead until all six cars were along the platform.10 

After the two trains had passed in the tunnel, the first and second mechanics did not see 

the senior mechanic. A search revealed that he had been struck and killed by the southbound 

train. They immediately notified the Operations Control Center. 

The southbound train operator said that he was about to radio the control center about the 

incident when an announcement came over the radio that someone had been struck by a train on 

track 1 at Dupont Circle. All passengers were directed to exit, and the train was secured in place. 

Sight-Distance Tests 

Safety Board investigators conducted postaccident sight-distance tests at the Dupont 

Circle interlocking. The tests revealed that the workers could be seen and recognized as wayside 

workers at a distance of about 280 feet. At a train speed of about 40 mph, the train operator thus 

would have been able to detect the wayside workers about 5 seconds before the train traveled 

past their location. 

Actions Taken in Response to Accident 

On June 26, 2006, WMATA issued Special Order 06-05, which added an additional 

paragraph to the Metrorail Safety Rules and Procedures Handbook. The new paragraph, Rule 

4.180k, follows: 

4.180k. To protect mainline work crews engaged in work for a period of more 

than three minutes at a stationary location on the right-of-way, restricted speeds 

entering the work site shall be established by using one of the following methods. 

The methods included the following, among others: place shunt straps at track locations 

that cause the automatic train control system to reduce train speeds to 15 mph through at least 30 

percent of the work area, use the automatic train control system to implement temporary speed 

restrictions in the affected area, and take action to force red (stop) aspects at approaches to the 

work area until all workers can be confirmed to be in the clear. The speed restrictions did not 

apply to inspections (as opposed to “hands-on” work), but inspectors could ask for restricted 

speeds if deemed necessary for safety.11

 10 When the operator of the striking southbound train returned to his job after the accident, he was retrained on 

the proper procedures that are required after an emergency brake application. 

11 After another fatal accident on the Metrorail system about 6 months after the Dupont Circle accident, 

WMATA, on February 22, 2007, issued Special Order 07-01, which superseded Special Order 06-05 and provided 

additional operational restrictions for train operators approaching work areas. WMATA subsequently issued Special 

Orders 07-02 and 07-06, which further revised or supplemented wayside safety rules and procedures. For more 

information, see <http://www.ntsb.gov/publictn/2008/RAB0802.pdf>, National Transportation Safety Board. 

Washington Metropolitan Area Transit Authority Train Strikes Wayside Workers Near Eisenhower Avenue Station, 
 

7

Probable Cause 

The National Transportation Safety Board determines that the probable cause of the 

Dupont Circle accident was the failure of the automatic train control system (senior) mechanic to 

stay clear of the approaching southbound train either because he was not aware of the presence 

of the train or because he lacked a physical reference by which to identify a safe area outside the 

train’s dynamic envelope. Contributing to the accident were Washington Metropolitan Area 

Transit Authority Metrorail right-of-way rules and procedures that did not provide adequate 

safeguards to protect the wayside personnel from approaching trains, that did not ensure that 

train operators were aware of wayside work being performed, and that did not adequately 

provide for reduced train speeds through work areas. Also contributing to the accident was the 

lack of an aggressive program of rule compliance testing and enforcement on the Metrorail 

system. 

Recommendations 

As a result of its investigations of this accident and a November 30, 2006, fatal accident 

involving the striking of wayside workers by a Metrorail Yellow Line train,12 the National 

Transportation Safety Board made the following safety recommendations to the Washington 

Metropolitan Area Transit Authority. (For more information about these recommendations, see 

the safety recommendation letter issued to the recipient.13) 

To the Washington Metropolitan Area Transit Authority: 

1. Review your Metrorail Safety Rules and Procedures Handbook and revise 

it as necessary to create additional layers of protection for wayside 

workers, including: 

• Adding requirements for wayside pre-work job briefings to ensure that 

all workers are informed of their duties, of their respective roles in 

work crew safety, and of the areas that are to be used to stay clear of 

trains. 

• Requiring that when train operators request permission to either enter a 

main track, or when a train is turned for a return trip, the train 

operators along the affected lines must acknowledge receipt of the 

updated radio announcement from the control center regarding 

wayside workers. 

 Alexandria, Virginia, November 30, 2006, Railroad Accident Brief NTSB/RAB-08/02 (Washington DC: NTSB, 

2008). 

12 See National Transportation Safety Board, Washington Metropolitan Area Transit Authority Train Strikes 

Wayside Workers Near Eisenhower Avenue Station, Alexandria, Virginia, November 30, 2006, Railroad Accident 

Brief NTSB/RAB-07/XX (Washington DC: NTSB, 2007). <http://www.ntsb.gov/publictn/2008/RAB0802.pdf> 

13 The recommendation letter is available on the Safety Board’s Web site at <www.ntsb.gov>. 
 

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• Establishing procedures to be used for members of a work crew to 

acknowledge a lookout’s warning that a train is approaching on a 

particular track from a particular direction before a lookout gives an 

all clear signal to a train. (R-08-01) 

2. Establish a systematic program for frequent unannounced checks of 

employee compliance with Metrorail operating and safety rules and 

procedures. (R-08-02) 

3. Perform periodic hazard analyses on the deficiencies identified by 

unannounced checks of employee compliance in response to Safety 

Recommendation R-08-02, and use the results to revise Metrorail training 

curricula or enforcement activities, as necessary, to improve employee 

compliance with operating and safety rules and procedures. (R-08-03) 

4. Promptly implement appropriate technology that will automatically alert 

wayside workers of approaching trains and will automatically alert train 

operators when approaching areas with workers on or near the tracks. 

(R-08-04) 

BY THE NATIONAL TRANSPORTATION SAFETY BOARD 

Mark V. Rosenker 

Chairman 

Deborah A. P. Hersman

Member 

Steven R. Chealander 

Member 

Robert L. Sumwalt 

Vice Chairman 

Kathryn O’Leary Higgins 

Member 

Adopted: January 23, 2008