Gantry (road sign)

A gantry is a traffic sign assembly in which signs are mounted on an overhead support.

Gantries are usually built on high-traffic roads or routes with several lanes, where signs posted on the side of the highway would be hard to see for drivers. Gantries may be cantilevered or one sided (sometimes referred to as a "half-gantry"), or they may be bridges with two sides. Similar gantries are used in railway signalling on multi-track lines.

Around the World

United Kingdom

Gantry signs are being installed at various locations around the trunk motorway network as increasing amounts of traffic mean that road signs at the side of the carriageway are constantly being obscured by large goods vehicles. They may also consist of variable message signs, and more recently Active Traffic Management, to close lanes due to accidents etc. They can also be used to specify temporary speed limits. Gantries in the United Kingdom display exit (junction) numbers, distances to junctions / exits (1 mile, 1/2 mile, 1/4 mile, 1/3 mile, 3/4 mile, 2/3 mile) and destinations reached, and if necessary what lane to use for them.

United States

Gantry signs are used frequently in the USA, particularly in urban areas where freeways have an exit every mile to fit in with the grid system. These 'half-gantries' usually have the exit number and the road/street that can be reached. Gantries can also span the whole carriageway, such as at major junctions.

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