For the accelerator interlock system, which prevents the accelerator from raising the engine speed above idle until the door has closed, the rod that stops the accelerator pedal being depressed is not secured at an appropriate position, and therefore the attachment part of the pedal may deform, if the pedal is depressed sideways while the accelerator interlock system is engaged. If the pedal is depressed further sideways, it may occur that the peal separates from the rod of the accelerator interlock system, causing the system not to work, or that the pedal is caught on the rod, in which case the engine revs would not drop.