1. Hidden highways: Fog and traffic crashes on America’s roads;Hamilon;2014 AAA Foundation for Traffic Safety Report,2014
2. A review of the literature pertaining to highway problems and possible solutions;Creech;Virginia Highway Research Council Report,1972
3. A study on crashes related to visibility obstruction due to fog and smoke;Abdel-Aty;Accident Analysis and Prevention,2011
4. Sensing visibility range at low cost in the SAFESPOT roadside unit;Hautière;ITS World Congress (ITS’09), Stockholm, Sweden,2009
5. Meteorological Office. Observers’ handbook. HMSO, London, 1969.