The first interim report on Project 77-02-3. "Sealing Cracks in Flexible Pavements", was submitted to the Oklahoma Department of Transportation (ODOT) in February, 1977 (1). This report contained a review of literature on the materials and methods of installation used in sealing flexible pavement cracks. The results of an in-state and surrounding state survey to determine currently used sealing materials and installation procedures and the effectiveness of this type of pavement maintenance were included. The report also suggested a three phase research approach directed to: 1) evaluating and/or developing laboratory test procedures that could be used to predict the field performance of sealant materials; 2) carrying out a field study of crack dynamics and; 3) conducting a field test program to evaluate the effectiveness of various application procedures and sealing materials. The project received additional funding and the second phase of the proposed research, the crack dynamics study, was started in March, 1977. This was a field study of transverse tcrack movements and behavior under varying conditions of load and temperatures. The purpose of the study was to obtain measurements of the relative horizontal and vertical movements of adjecent pavement sections at transverse cracks in the roadwya surface. Such data were considered necessary in order to establish reasonable performance criteria for sealants based on average Oklahoma conditions.