National Research Council (U.S.) text Washington, D.C Transportation Research Board, National Research Council, National Academy of Sciences 1983 monographic iv, 31 p. : ill. ; 28 cm. 0 0 0 380_500000000000000_NAT MCE Roads Maintenance and repair Safety measures Roads Snow and ice control Traffic signs and signals 380.5 NAT 0309036232 (pbk.) :