[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR234.227] [Page 588-589] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 234_GRADE CROSSING SIGNAL SYSTEM SAFETY--Table of Contents Subpart D_Maintenance, Inspection, and Testing Sec. 234.227 Train detection apparatus. (a) Train detection apparatus shall be maintained to detect a train or railcar in any part of a train detection circuit, in accordance with the design of the warning system. [[Page 589]] (b) If the presence of sand, rust, dirt, grease, or other foreign matter is known to prevent effective shunting, a railroad shall take appropriate action under Sec. 234.105, ``Activation failure,'' to safeguard highway users.