Median strip

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, rapid transit, light rail, or streetcar lines.

Variants in North American English include regional terms such as neutral ground in New Orleans usage or boulevard in Vancouver, British Columbia.

Such medians are also sometimes found on more minor or residential streets, where they serve primarily as a traffic-calming or landscaping element rather than a safety enhancement to restrict turns and separate opposite directions of high-volume traffic flow.

The central reservation in the United Kingdom and other densely populated European countries (where it is known by their local names) is usually no wider than a single lane of traffic.

With effect from January 2005 and based primarily on safety grounds, the UK's Highways Agency's policy is that all new motorway schemes are to use high containment concrete step barriers in the median (central reservation).

All existing motorways will introduce concrete barriers as part of ongoing upgrades and through replacement as and when the current systems have reached the end of their useful life.

An extreme example of a wide median can be found on Interstate 75 near Cincinnati, Ohio; nearly the entire village of Arlington Heights, as well as the downtown district of Lockland, are both located between the two directions of I-75.

Some freeways in North America include "inverted" medians, which separate roadways running in the opposite direction from the standard for the country they are located in.

An August 1993 study by the US Federal Highway Administration quantified the correlation between median width and the reduction of both head-on accidents and severe injuries.

Center-lane running and island platforms installed in the medium reduce conflicts with stopped and parked cars as well as pedestrians near the curb, thus speeding service.

Some of the earliest practices of incorporating central tramways into road designs were pioneered in Liverpool by John Alexander Brodie, and later emulated in Manchester, such as along Princess Parkway or Kingsway.