This vehicle includes a guard rail intended to occupy a lowered position delimiting a closed space that prevents a passenger from falling and a raised position in which the guard rail opens up the space at the front of the vehicle to allow one or more passengers to board and disembark. The vehicle also includes means for locking the guard rail in the lowered position, wherein the locking means includes a locking lever having a first end provided with a bearing surface and with a blocking surface, the bearing surface and the blocking surface delimiting a first housing intended to accommodate part of the guard rail, and a second end in which a locking member designed to immobilize the second end of the locking lever is intended to engage when the guard rail is in the lowered position.