A central reservation, also known as a median strip, is a narrow piece of land that divides the two parts of a motorway or other main road. It is the reserved area that separates opposing lanes of traffic on divided roadways. The central reservation in the United Kingdom and other densely populated European countries is usually no wider than a single lane of traffic. In some cases, however, it is extended. For instance, if the road is running through hilly terrain, the carriageways may have to be built on different levels of the slope.

Central reservations may simply be paved, but commonly they are adapted to other functions; for example, they may accommodate decorative landscaping, trees, a median barrier, or railway, rapid transit, light rail, or streetcar lines. In the UK, with effect from January 2005 and based primarily on safety grounds, all new motorway schemes are to use high containment concrete step barriers in the 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.