Skid Characteristics of Pavement Surfaces in Indiana

In 1953, drivers in the United States became involved in 31,450 fatal and 1,302,000 non-fatal accidents. Many of these accidents were primarily the fault of the drivers involved, but a great number might have been minimized or prevented by safer highways. Although many factors are involved in the building of safety into highways, one of the more important items is the resistance of pavement surfaces to skidding, especially when these surfaces are wet. Twenty per cent of the fatal and 23 per cent of the non-fatal accidents in 1953 occurred on wet pavements. When consideration is given to the fact that pavements are wet far less than 20 per cent of the time, and travel is usually reduced during wet periods, it is evident that a disproportionate number of accidents occur under these conditions. How many accidents could be avoided by better skidding characteristics is unknown; but since many accidents involve some type of skidding, the number is undoubtedly great. In Indiana, it is generally recognized that certain types of pave­ ments have better skidding characteristics than others, but few measure­ ments have ever been taken on a comparative basis. Experimental sec­ tions have been constructed in the past few years, and several new surface types are being used. Some of these surfaces are quite economical and durable, but little is known of their skidding properties. If the new surfaces are dangerously slippery the reduced construction cost is of extremely dubious value, unless they can be redesigned so as to make them satisfactory. The need for a method of determining skidding properties that is fast, safe, and accurate, and the determination of the skidding char­ acteristics of pavement surfaces is, therefore, evident.