PURPOSE: To freely operate a shift lever at the time of stopping power transmission.

CONSTITUTION: A transmission operation device for a travel gear has a return spring 3 between a shift lever 32 having a brake lever 60 and frictionally holding a position for continuously variable transmission, and the interlock arm 34 of a transmission interlock mechanism 61 interlocked with the lever 32 for changing the speed of a continuous variable transmission belt, so that the arm 34 can be returned to a constant position relative to the shift lever 32.