Based on new experimental results of Chpoun, Passerel, Li, and Ben‐Dor [J. Fluid Mech.301, 19 (1995)] and numerical results of Vuillon, Zeitoun, and Ben‐Dor [J. Fluid Mech.301, 37 (1995)] regarding the shock wave reflection transitions from regular to Mach reflection and from Mach to regular reflection in steady flows of perfect gases which contradicted the present understanding regarding these processes [Hornung and Robinson, J. Fluid Mech.123, 155 (1982)], we present a new approach for better understanding the supersonic flow deflection over straight wedges and the transition of steady shock wave reflections over straight wedges. The new approach is based on the principle of minimum entropy production which enables one to choose the physical (stable) solutions out of a variety of possible mathematical ones. To the best of our knowledge the new transition criteria which are proposed in this study agree with all the available experimental results. ©1996 American Institute of Physics.