The following words used in sections 389.991 to 389.995 shall mean:
(1) "Bridges", structures supporting the track or tracks over a waterway, highway, ravine or railroad;
(2) "Carrier", any common carrier by rail;
(3) "Division", the motor carrier and railroad safety division of the department of economic development;
(4) "Roadbed", culverts, tunnels, cuts and fills on which or through which the tracks are located;
(5) "Tracks", rails and fastenings, ties, crossings-at-grade, both railroad and highway, switches and their appurtenances but not including signal equipment.