Abstract: A transmission shift control mechanism for preventing inadvertent movement toward the reverse gear engaging position during forward upshifting or downshifting, thereby reducing the forward shift time and thus reducing harmful engine emissions. The shift lever is guided in its movement between shift rails, and blocked from moving to the reverse shift rail engaging position until an additional movement is made. Shift rail collars define shift lever guides, the reverse one of which is offset from the forward guides to thereby require the additional movement of the shift lever.