In this paper, the results of a study of the problem of the spare ratio in the bus transit industry are examined. Statistical techniques were used to investigate the relationships between variations in spare ratio and characteristics of bus transit properties. Section15 data for 1984 were used as the basis of the analysis. The use ofcluster and discriminant analyses made it possible to specify 14 important variables that affect the spare ratio and use them collectively to classify properties into three groups, with high, average, orlow spare ratios. It was determined that there is a significantly lower average total number of road calls per vehicle hour for properties that have a low spare ratio than there is for those that have medium or high ratios. Mechanical and total road calls per vehicle mile exhibit similar patterns. The percentage of federal assistance to total revenue has a lower average in systems with lower spare ratios, which means that properties that have high spare ratios have relied on federal assistance more than have those that have low spare ratios. This paper appears in transportation research record no. 1221, Research in bus and rail transit operations.
Abstract