​On August 4, 2023, about 10:05 a.m., the operator of a roadway maintenance machine (RMM) struck and killed a Middlesex Corporation employee performing track work on the Berkshire Line in Great Barrington, Massachusetts. The RMM involved in the accident was a tie drilling machine, which is commonly referred to as a driller. About an hour before the accident, the driller experienced a mechanical issue that required the driller operator to remove the driller from the work location for repairs. The driller operator was part of a four-member work group of Middlesex employees; one of those employees accompanied him when he departed the job location on the driller, while the other two employees remained working (on foot) at the job location. After repairs had been made to the driller, the driller operator traveled about 1.4 miles in reverse along the Berkshire Line back to the job location to resume work. While conducting this reverse movement, the driller operator did not see that his two fellow Middlesex employees, who had remained working at the job location, were on the same track as the RMM; subsequently, the driller struck and killed one of the employees.​

​We determined that the probable cause of the Great Barrington, Massachusetts, roadway maintenance worker fatality was the Middlesex Corporation driller operator’s failure to actively observe that the driller’s path of travel was clear. 

Contributing to the accident was:

• the Housatonic Railroad Company roadway worker-in-charge’s (RWIC) lack of awareness of daily tasking, which prevented him from conducting an adequate job briefing for all tasks being performed, 
• the RWIC’s lack of awareness of on-track roadway maintenance machine movements without his knowledge or authorization, 
• the absence of a required second RWIC for work group 2, and
• no communications between the RWIC and work group 2 about their work activities prior to the accident, which resulted in his lack of awareness that a second work group or work site existed.
  

As a result of this investigation, the National Transportation Safety Board makes the following new safety recommendations. ​​Read the complete list of recomme​ndations​.​​​

To the Federal Railroad Administration:

• ​​Require all on-track roadway maintenance machines (RMMs) to be equipped with collision avoidance systems that can detect people, objects, or other machines on the ground and automatically stop the RMM before a collision. (R-25-6)
• Require on-track roadway maintenance machines with booms or other movable extensions to be equipped with a 360° people detection system that covers the length of the boom or extension in all directions and alerts operators when people are within an unsafe proximity. (R-25-7)
  

​To all Class I Railroads, the Housatonic Railroad Company, and Middlesex Corporation:​ ​

• Require all on-track roadway maintenance machines (RMMs), including leased or contracted RMMs, to be equipped with collision avoidance systems that can detect people, objects, or other machines on the ground and automatically stop the RMM before a collision. (R-25-8)

​To all Class I Railroads:​​

• Require all on-track RMMs with booms or other movable extensions, including leased or contracted RMMs, be equipped with a 360°people detection system that covers the length of the boom or extension in all directions and alerts operators when people are within an unsafe proximity. (R-25-9)

​To the American Short Line and Regional Railroad Association and the National Railroad Construction and Maintenance Association:

• ​​​Inform your members of the safety benefits of equipping roadway maintenance machines (RMMs) with collision avoidance systems and, when RMMs have movable extensions, a people detection system that alerts operators of nearby workers. (R-25-10) ​​