Highway median

The median strip or central reservation is the reserved area that separates opposing lanes of traffic on divided roadways, such as divided highways, dual carriageways, freeways, and motorways. The term also applies to divided roadways other than highways, such as some major streets in urban or suburban areas. The reserved area may simply be paved, but commonly it is adapted to other functions; for example, it may accommodate decorative landscaping, trees, a median barrier or railway, light rail or streetcar lines.

There is no international English standard for the term. Median, median strip, and median divider island are common in North American and Antipodean English. Variants in North American English include regional terms such as neutral ground in New Orleans usage.

In British English central reservation is the preferred usage; it also occurs widely in formal documents in some non-British regions such as South Africa, where there are other informal regional words, for example middelmannetjie, which originally referred to the hump between wheel ruts on a dust road. Among other coinages, central nature strip occurs in Australian English.

Additionally, different terminology is used to identify traffic lanes in a multi-lane roadway. North American usage calls the lanes located closest to the roadway centerline the "inner" lanes, while British usage calls these lanes the "outer" lanes. Thus, it is less confusing to call these central lanes the "passing", "fast", or "overtaking" lanes in international contexts, instead of using the ambiguous inner/outer distinction. Regional differences between right-hand traffic and left-hand traffic can cause further confusion.

...
Wikipedia