線路
せんろ · senro · JLPT N2 · noun
roadbed
🛤️ 線 (line, thread) + 路 (road, path) = the road made of lines: railway track
The same 線 appears in 電線 (power line). Since 路 means road, 線路 is literally a road made of rails.
路 — foot 足 + each 各 (phonetic)
路 is a semantic-phonetic compound. The foot radical 足 on the left signals meaning related to walking or travel, while 各 on the right hints at the ancient pronunciation. Originally referring to a road traveled on foot, it broadened to mean 'road, path, route' in general.