Item: LOOKING BACK—30 YEARS OF IMPACT: A CALTRANS GAZEX RACS HISTORY
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Title: LOOKING BACK—30 YEARS OF IMPACT: A CALTRANS GAZEX RACS HISTORY
Proceedings: Proceedings, International Snow Science Workshop, Whistler, BC, Canada, 2026
Authors:
- Ryan Marvin [ MND Safety, USA ]
Date: 2026-09-28
Abstract: Since its introduction in the early 1990s, Gazex Remote Avalanche Control Systems (RACS) have become a central component of avalanche hazard management on several California mountain highways. Prior to the adoption of Gazex, the California Department of Transportation (Caltrans) relied heavily on artillery and hand-delivered explosives to mitigate avalanche hazard, with thousands of rounds fired from 75 mm recoilless rifles each year. Aging military ammunition and increasingly poor reliability ultimately created a need for an alternative mitigation system. Caltrans began installing Gazex exploders in 1992, with early installations at Echo Summit, Carson Spur, Carson Pass, and the June Lake area. Over more than three decades of operation, these Remote Avalanche Control Systems have changed not only the tools available to Caltrans but also the program's efficiency, safety, timing and the greater philosophy of its avalanche program. Operations that were historically more reactive and labor intensive can now be conducted proactively, rapidly, and with substantially less personnel exposure. Many lessons have been learned during Caltrans tenure with Gazex systems. In the early days, operations were characterized by inadequate maintenance, unnecessarily frequent firing, and limited protocols or documentation. A renewed emphasis on yearly maintenance, and a year-round team of dedicated avalanche personnel has increased system firing reliability to greater than 99% reliability on the present day shot rate amongst all 53 of the state's exploders. This paper examines more than three decades of RACS use within Caltrans, and the continuing role of conventional and remote avalanche control methods within a modern highway avalanche program. We will discuss the operational problems that led to its adoption, lessons learned during implementation, changes in mitigation strategy and efficiency, lessons learned, and the limitations that remain with the widespread use of remote avalanche control.
Object ID: ISSW2026_P2.20.pdf
DOI: https://doi.org/10.15788/1790098932
Language of Article: English
Presenter(s): Ryan Marvin
Keywords: GAZEX, remote avalanche control, highway avalanche mitigation, Caltrans, avalanche safety, RACS
Page Number(s): 802 - 809
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