路基

lùjī
(civil engineering) roadbed

CEDICT

roadbed

Wiktionary

铁路或公路的道路基础地层。视地形和土质状况可分成开挖天然地面而成的路堑与人工堆筑而成的路堤。

重編國語辭典

Entry Composition

1 路 lù
  1. journey
  2. route
  3. line (bus etc)
  4. sort; kind

classifier: 條
2 基 jī
  1. (bound form) base; foundation
  2. (bound form) radical (chemistry)
  3. (bound form) gay (loanword from English into Cantonese, Jyutping: gei1, followed by orthographic borrowing from Cantonese)