In 2000, the Maryland Transit Administration (MTA) experienced two similar accidents in the same location just 6 months apart. Both accidents involved the failure of an MTA light rail vehicle (LRV) train to stop at the designated stopping point at the Baltimore-Washington International Airport Light Rail Station (BWI Airport Station). In both cases, the train struck a hydraulic bumping post apparatus at the end of the track. The Safety Board's investigation of the two accidents indicated that, although the direct cause of each accident was different, aspects of the MTA rail transit operation common to the two accidents influenced both their outcomes. Consequently, the Safety Board developed a special investigation report to address the safety factors affecting both accidents.
The first accident occurred about 2:37 p.m. (eastern standard time) on February 13, 2000, when MTA train 24 (composed of a single LRV), en route from Baltimore to the BWI Airport, struck the hydraulic bumping post at the terminus of track No. 1 at the BWI Airport Station and derailed. The force of the collision detached the bumping post from the track, and the front of the train, which was lodged against the bumping post, was elevated about 3 1/2 feet into the air. Train 24 carried 26 people (25 passengers and 1 operator), 18 of whom were injured. Five of those injured had serious injuries. The MTA estimated the cost of the accident at $924,000.
The second accident occurred about 7:14 a.m. (eastern daylight time) on August 15, 2000, when MTA train 22 (composed of two LRVs), en route from Baltimore to the BWI Airport, struck the hydraulic bumping post at the terminus of track No. 2 at the BWI Airport Station and derailed. The bumping post separated from its attachment to the track and came to rest in an inverted position. The leading LRV of the train came to rest on top of the overturned bumping post and about 4 1/4 feet up in the air. The roof of this LRV was partially embedded into the ceiling structure of the terminal building. Train 22 carried 22 people (21 passengers and 1 operator), 17 of whom were injured. None had lifethreatening injuries. The MTA estimated the cost of the accident at $935,000.
The Safety Board determines that the probable cause of the February 13, 2000, accident at the Baltimore-Washington International Airport rail transit station was the train 24 operator's impairment by illicit and/or prescription drugs, which caused the operator to fail to stop the train before it struck the bumping post at the terminus.
The Safety Board determines that the probable cause of the August 15, 2000, accident at the Baltimore-Washington International Airport rail transit station was the train 22 operator's severe fatigue, resulting from undiagnosed obstructive sleep apnea, which caused the operator to fall asleep so that he could not brake the train before it struck the bumping post at the terminus.
This special investigation report discusses the following safety issues:
- The adequacy of requirements governing the use of prescription and over-thecounter medications by LRV operators,
- The effect of sleeping disorders on the performance of LRV operators,
- The adequacy of the event recorders.
As a result of its investigation of these accidents, the Safety Board makes recommendations to the Federal Transit Administration, U.S. rail transit systems, and the MTA.
As a result of its investigation of both accidents discussed in this report, the National Transportation Safety Board makes the following safety recommendations:
To the Federal Transit Administration
Authorize and encourage rail transit systems to require their employees in safety-sensitive positions to inform the rail transit system about their use of prescription and over-the-counter medications so that the rail transit system can have qualified medical personnel determine the medication's potential effects on employee performance. (R-01-25)
To U.S. rail transit systems
Require employees in safety-sensitive positions to inform their supervisors when they are using prescription or over-the-counter medications so that qualified medical personnel may determine the medication's potential effects on employee performance, and train the employees about their responsibilities under the policy. (R-01-26)
Ensure that your fatigue educational awareness program includes the risks posed by sleeping disorders, the indicators and symptoms of such disorders, and the available means of detecting and treating them. (R-01-27)
To the Maryland Transit Administration
Install, on all your light rail vehicles, independent event recorders that record and retain the most recent 48 hours of data, store data in nonvolatile memory, and have a back-up power source that would enable the entire recording system to function if electric power is lost to the car. (R-01-28)