"Roadside billboards" refers to large advertising signs or posters that are strategically placed along the side of a road or highway in order to catch the attention of people driving or walking by. Full definition
Nearly a year after her daughter's murder, Mildred Hayes (Frances McDormand) expresses her outrage by buying up advertising space on three adjacent roadside billboards in Ebbing, Mo.. (creativeplanetnetwork.com)
Inspired by angry roadside billboards he saw while on a trip through the southern United States, McDonagh («In Bruges,» «Seven Psychopaths») hypothesized the advertisements coming from a woman wronged. (backstage.com)
Think a dash of Chinatown's noir sprinkled over Boogie Nights, and you're in the ballpark, with Nixon on the cover of Forbes, Jaws 2 decorating roadside billboards and exquisite period details shining on every corner. (timeout.com)