The highway revolution 1895 1925 : how the United States got out of the mud To get out of the mud : who pays What kind of road the Macadam Era Educating rural highway builders : getting out the word on construction methods Horse drawn road machinery Steam powered machines for highway building The contractor The long road from asphalt streets to asphalt highways Gasoline power and highways Cement concrete and mixers Concrete highways : the boom years 1914 1925 Retrospect on a revolution