A SYSTEM FOR PLANNING ROADWAY IMPROVEMENTS

A SYSTEM FOR PLANNING PAVEMENT IMPROVEMENTS HAS BEEN DEVELOPED THAT TAKES INTO CONSIDERATION THE MAIN ELEMENTS AFFECTING ROADWAY PERFORMANCE. THERE ARE FOUR ELEMENTS INVOLVED IN THE SYSTEM: (1) SUFFICIENCY: THE SAFE MOVEMENT OF TRAFFIC OVER THE ROADWAY AT DESIGN SPEEDS. THIS INCLUDES SUCH ITEMS AS CAPACITY, HAZARDS, GEOMETRICS, ETC. (2) STRUCTURAL ADEQUACY: THE ABILITY OF THE ROADWAY TO SUPPORT REPEATED TRAFFIC LOADS WITHOUT FAILURE. (3) SERVICEABILITY: AN ESTIMATE OF THE TRAVELING PUBLIC'S OPINION OF THE RELATIVE QUALITY OF PAVEMENT SURFACES. (4) SLIPPERINESS: THE SKID RESISTANCE OF PAVEMENT SURFACES. THE PRESENT CONDITION OF THE ROADWAYS IS EVALUATED ACCORDING TO EACH ELEMENT. USING APPROPRIATE PREDICTION EQUATIONS, THE RATE OF DETERIORATION OF A PAVEMENT IS DETERMINED AND, IN RELATIONSHIP TO TRAFFIC, THE TIME OF FAILURE IS PREDICTED. THE REQUIRED SERVICE LIFE FOR A PAVEMENT IS BASED ON SUFFICIENCY AND BUDGET LIMITATIONS. THE REMAINING LIFE FROM EACH OF THE OTHER THREE ELEMENTS IN CONJUNCTION WITH THE REQUIRED SERVICE LIFE IS USED TO DETERMINE THE RECOMMENDED IMPROVEMENT THAT WOULD BE NECESSARY TO MAINTAIN THE ROADWAY AT A SATISFACTORY LEVEL OF PERFORMANCE. THIS SYSTEM PERMITS DETERMINING WHEN ROADWAY IMPROVEMENTS WILL BE REQUIRED, WHAT TYPE OF IMPROVEMENT, AND THE AMOUNT OF CORRECTION NECESSARY FOR THE ROADWAY TO MAINTAIN A SATISFACTORY LEVEL OF PERFORMANCE FOR ITS INTENDED LIFE. /AUTHOR/