Riding tractor for supporting a mower unit

A riding tractor in which engine output is transmitted to a running device through a hydrostatic stepless transmission, comprising:

• a brake device for acting on said running device;
• a first brake operating device for operating said brake device;
• a second brake operating device operable independently of said first brake operating device for operating said brake device;
• a lost motion mechanism provided between said first brake operating device and said second brake operating device, said lost motion mechanism being operable not to transmit a control displacement of said first brake operating device to said second brake operating device when said first brake operating device operates said brake device;
• and
• a brake lock mechanism movable with said first and second brake operating devices, and switchable between a locking state for locking said brake device to a braking position, and a lock release state for unlocking said brake device from said braking position,
• wherein said brake lock mechanism in said lock release state maintains said lock release state when only said first brake operating device operates said brake device to said braking position and automatically switches from said lock release state to said locking state when said first brake operating device and said second brake operating device operate said brake device to said braking position, and
• said brake lock mechanism in said locking position is switchable to said lock release position by the control displacement of said first brake operating device.