(BRK.A), (BRK.B)
BNSF marked a significant rail safety achievement on Dec. 9, 2025, with the full implementation of positive train control (PTC) technology on the former Montana Rail Link (MRL) lines. The rollout began in June with 36 miles placed into service, followed by three additional segments, bringing the total to more than 216 miles of PTC protection on the MRL Subdivision within BNSF’s Montana Division.
The milestone reflects more than two decades of investment by BNSF in PTC, a critical safety system designed to prevent train-to-train collisions, derailments caused by excessive speed, and unauthorized train movements. PTC also protects employees working on the track and ensures trains do not move through switches that are improperly aligned.
Across its network, BNSF has installed PTC on nearly 17,000 miles of track—well above the approximately 15,000 miles mandated by the Federal Railroad Administration. According to Phil Mullen, director of Network Control Systems, BNSF chose early on to exceed regulatory requirements to enhance safety for employees, the public, and the communities it serves. The MRL installation was completed four months ahead of the federal deadline through close coordination between network control, signal teams, and Montana Division leadership.
PTC integrates digital wireless communications, GPS, and onboard computing to provide locomotive crews with real-time information on speed limits, authority boundaries, work zones, and upcoming signals and switches. By issuing warnings and automatically stopping trains when necessary, the system not only prevents violations but also improves situational awareness and operational efficiency. As BNSF continues to refine and expand PTC, the technology remains a cornerstone of the company’s commitment to safe and efficient rail operations.
© 2026 David Mazor
Disclosure: David Mazor is a freelance writer focusing on Berkshire Hathaway. The author is long in Berkshire Hathaway, and this article is not a recommendation on whether to buy or sell the stock. The information contained in this article should not be construed as personalized or individualized investment advice. Past performance is no guarantee of future results.