[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR236.4] [Page 639] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 236_RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, Subpart A_Rules and Instructions: All Systems Sec. 236.4 Interference with normal functioning of device. The normal functioning of any device shall not be interfered with in testing or otherwise without first taking measures to provide for safety of train operation which depends on normal functioning of such device. [49 FR 3382, Jan. 26, 1984]