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Centralized Interlocking (CIXL) for Moving Block Research Project

Document Series:
Research Results
Author:
  • Federal Railroad Administration
Report Number
RR 21-07
Office
RDI-23
Subject:
Positive Train Control
Keywords:
Centralized interlocking system, CIXL, Quasi-Moving Block, QMB, Positive Train Control, PTC, Communications-Based Train Control, CBTC, control point, CP, Wayside Status Messages, WSM, railroad, train control
Document
CIXL Moving Block Research.pdf (463.86 KB)

From September 9, 2019, to March 8, 2021, the Federal Railroad Administration (FRA) sponsored Transportation Technology Center, Inc. (TTCI), to develop and analyze a concept for a centralized interlocking (CIXL) system that supports moving block methods of train control, improves overall availability and maintainability, and satisfies the needs of North American railroads.


Last updated: Wednesday, August 20, 2025