Despite the growing knowledge concerning JPCP, some pavements of this type still suffer premature failure in the first years of service. The most common failure types include longitudinal, transverse and expansion joint cracks. This paper presents the results of a field study of JPCP on the major road network in Poland that have suffered premature cracking in the early years of service. The analyses are based on pavement condition assessment, non-destructive dowel position measurements using MiT-Scan2-BT and measurements of the extent of cracks in the slabs performed with MIRA A1040 3D. Based on the measurement of the position of the dowels, an equivalent diameter algorithm was used to assess the compressive stresses of the concrete in the dowel cover (under the dowel). Construction documents were analysed to determine the layout of the pavement layers and to calculate the thermal load prevailing during the concreting and curing periods of the JPCP. A pull-out test of non-greased and greased dowels was carried out in the laboratory to increase the free movement. All laboratory tests and analytical results from a separate work were used in calculations performed on the pavement model in the finite element method (FEM), from which the probable cause of premature cracking of the JPCP was determined.