As used in sections 219.559 and 219.56, the following terms have the meanings given them:

1. (a) "Caboose" means a railroad car or coach that meets the standards of section 219.56 and is used on a train to carry a train crew.
2. (b) "Terminal" means a system of tracks, whose boundaries are set by a railroad, used for coupling or uncoupling cars.
3. (c) "Placarded car" means a railroad car that is required by federal regulations to display placards because the car contains hazardous materials.
4. (d) "Block signals" means a series of signals that control the movement of trains within a section of track.