TY - BOOK TI - Motorist information systems 8 reports prepared for the 51st Annual Meeting. T3 - Highway research record CY - Washington PB - Highway Research Board PY - 1972 LA - English N1 - Papers presented at the 51st Annual Meeting of the Highway Research Board, January 1972. Sponsored by Committee on Motorist Information Systems, and Committee on Highway-Railroad Grade Crossings. ER -