aerial view of train track, treated rail sleeper and pebble ballast

tie crosstie fasteners pad railroadiana railroad locomotive travel transportation mass transit commuter train trax clamp pad joints infrastructure old fashioned antiquated retro modern clip horizontal vertical polka dot pattern linear straight immobile immobility secure secured passenger line freight smooth rough steel molybdenum repair maintenance expansion heat heated cold welding welded standard narrow gauge metallurgy metallurgical nail spike treated wood creosote travel explore exploration right angle security