Public Roads;Federal Highway Administrationhttps://doi.org/10.21949/15236841937PDFJournalPeabody, L. E.Spasoff, I. MansfieldUnited States. Department of Agriculture. Bureau of Public Roads{65771}United States. Government Printing Office{1103}United StatesStudiesInfrastructureResearchStatisticsHIGHWAY STATISTICSVolume 18, Issue(s) 6These documents are disseminated under the sponsorship of the U.S. Department of Transportation, Federal Highway Administration, in the interest of information exchange.The U.S. Department of Transportation does not endorse any manufacturers, products, or services cited herein and any business or trade names that may appear in these documents have been included only as necessary to further the purpose of the docum...