[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR218.23] [Page 198] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 218_RAILROAD OPERATING PRACTICES--Table of Contents Subpart B_Blue Signal Protection of Workers Sec. 218.23 Blue signal display. (a) Blue signals displayed in accordance with Sec. 218.25, 218.27, or 218.29 signify that workers are on, under, or between rolling equipment. When so displayed-- (1) The equipment may not be coupled to; (2) The equipment may not be moved, except as provided for in Sec. 218.29; (3) Other rolling equipment may not be placed on the same track so as to reduce or block the view of a blue signal, except as provided for in Sec. 218.29 (a), (b) and (c); and (4) Rolling equipment may not pass a displayed blue signal. (b) Blue signals must be displayed in accordance with Sec. 218.25, 218.27, or 218.29 by each craft or group of workers prior to their going on, under, or between rolling equipment and may only be removed by the same craft or group that displayed them.