Abstract: A brake pedal device suitable for being actuated to effect service braking and lock braking, said brake pedal device having a first brake pedal element and a second brake pedal element, which elements are suitable for being moved by being depressed for effecting braking. Depression of at least the first brake pedal element is suitable for causing service braking to take place. The device further has locking means which are suitable for being activated by moving the second brake pedal element over a determined stroke only, so as to hold said second brake pedal element in the locked position for lock braking, and unlocking means which are suitable for being activated by depressing the first brake pedal element so as to unlock the locking means and so as to release the second brake pedal element.