Allerta is an open sourcetypeface intended for use on public signage (such as traffic signs). It was released in 2009 by Matt McInerney. The typeface consists of two fonts, one in medium-weight and the other divided into sections so it can be cut into stencils. The font was designed with readability as the foremost priority and features alphanumeric characters designed to look as different as possible. In addition to the alphanumeric characters, the font includes more than a dozen pictograms featuring icons to indicate the presence of buses, medical assistance, and arrows pointed in eight directions.
Along with the fonts, McInerey's release included a "kit" in the form of a vector illustration designed to easily assist someone in printing and cutting actual stencils that can be used to paint signs in an emergency situation.
The name of the font was derived from the Italian language word all'erta, literally meaning "on the lookout."