Highway 400

The following highways are numbered 400:

Australia

* Murray Valley Highway

Canada

* Ontario Highway 400

Croatia

* D400 road

Cuba

* Vía Monumental (2–400)

Ireland

* R400 road (Ireland), R400 road

Japan

* Japan National Route 400

Korea, South

* Capital Region Second Ring Expressway

South Africa

* R400 road (South Africa), R400 road in the Eastern Cape

Spain

* N-400 road (Spain), N-400 road

Turkey

* , a west–east state road in Turkey running from Datça, Muğla Province to Esendere at the Iranian border.

United Kingdom

* A400 road (Great Britain), A400 road in London
*B400 road (Chancery Lane)

United States

* U.S. Route 400
* Arkansas Highway 400
* Florida State Road 400
* Georgia State Route 400
* Kentucky Route 400
* Louisiana Highway 400
* Maryland Route 400, a former state highway
* Nevada State Route 400
* New York:
** New York State Route 400
** County Route 400 (Erie County, New York)
* North Carolina Highway 400
* Pennsylvania Route 400 (official designation for Pennsylvania Route 380)
* Puerto Rico Highway 400
* South Carolina Highway 400
* Tennessee State Route 400
* Texas:
** Texas State Highway Spur 400
** Farm to Market Road 400
* Utah:
** Road 400 (Cottonwood Canyon Road)
* Virginia State Route 400
** State Route 400 (Virginia 1928), Virginia State Route 400 (former)

{{Road index, 400