United Kingdom

The M25, a typical motorway in the United Kingdom

In the UK the term motorway is used almost unanimously to refer to a specific type of road in the UK and the Republic of Ireland. Although the terms expressway, or parkway are sometimes used, they amount to little more than street names, with motorway the only term officially recognized. The UK motorways are engineered so that they are among the safest such roads in the world, with almost all motorways having a full-width hard shoulder (breakdown lane), full grade-separated interchanges with long on/off ramps and a barriered central reservation which is a compulsory requirement for a motorway (the term “median strip” is unknown in British English). Without a barried central reservation, or if a multilane road fails to meet any of the other requirements to become a motorway, it is simply referred to as a dual carriageway.

All UK motorways have an “M” prefix (e.g. M1) or, where an “A” road has been upgraded to motorway status, an “M” suffix in brackets (e.g. A1(M)).