Joints in jointed concrete pavements are artificially designed discontinuities to control the natural cracking with slab movements caused by changes in temperature and moisture conditions. However, considerable portion of joints are not cracked in practice. In this study, joint-uncracking phenomenon are categorized by two patterns, prior mid-slab cracking pattern (Case A) and low tensile-stress pattern (Case B). Prior mid-slab cracking pattern indicates that mid-slab cracking occurs before saw cutting at joints and joints remains as uncracked. Low tensile-stress pattern indicates that some portions of joint are cracked and others remains uncracked without mid-slab cracking since tensile stress, developed by subbase friction and curing, is lower than minimum stress to crack at joints. The causes of and frequencies of joint-uncracking are investigated in a number of jointed concrete pavements (JCP) in USA and Korea. The uncracked joints result in longer-concrete-pavement slab than the designed. In this study, the effects of uncracked joints such as the erratic large joint opening and excessive slab stress are explored.