REPORT OF COMMITTEE ON MAINTENANCE: V. MAINTENANCE COSTS AS AFFECTED BY THE TYPE OF PAVEMENT AND AMOUNT OF TRAFFIC

THE GENERAL BELIEF THAT THE HIGHER TYPES OF PAVEMENT ARE THE MOST ECONOMICAL IN MAINTENANCE COST SEEMS TO BE BORNE OUT BY THE MAINTENANCE RECORDS OF THE PENNSYLVANIA DEPARTMENT OF HIGHWAYS DURING THE LAST THREE YEARS. IN CONNECTION WITH THESE FIGURES, HOWEVER, IT IS NECESSARY TO BEAR IN MIND THAT THE DURABLE TYPES WHICH SHOW THE LOWEST ANNUAL COSTS ARE OF COMPARATIVELY RECENT CONSTRUCTION AND THEIR MAINTENANCE COSTS ARE LIKELY TO INCREASE WITH THEIR AGE. IN STUDYING MAINTENANCE COSTS OF VARIOUS TYPES, IT IS IMPERATIVE TO KEEP IN MIND THE FACT THAT THE MAINTENANCE COSTS ARE ONLY A PART OF THE TOTAL ROAD COSTS; THAT THE VARIOUS TYPES DO NOT FURNISH EQUAL ROAD SERVICE. THE INDICATIONS ARE THAT EVERY TYPE OF ROAD HAS A CRITICAL TRAFFIC POINT WHICH IS HIGHER FOR HIGH TYPE ROADS THAN FOR LOW TYPE ROADS. WHEN THIS TRAFFIC POINT IS PASSED MAINTENANCE COSTS MOUNT RAPIDLY.