central reservation
noun🔊/ˌsentrəl rezəˈveɪʃn/
🔊/ˌsentrəl rezərˈveɪʃn/
(British English) (North American English median, median strip)
a narrow piece of land that separates the two sides of a major road such as a motorway or interstate （高速公路、州际公路等的）中央隔离带