
    Calculate the total length of safety barriers needed to fully enclose a square ride-sharing pickup zone, given the zone's side length in meters. The barriers must run continuously along all four sides of the designated area to ensure passenger safety and orderly vehicle queuing.
    

    
def square_perimeter(a):
    """
    Calculate the total length of safety barriers needed to fully enclose a square ride-sharing pickup zone, given the zone's side length in meters. The barriers must run continuously along all four sides of the designated area to ensure passenger safety and orderly vehicle queuing.
    

    """
def square_perimeter(a):
    """
    Calculate the total length of safety barriers needed to fully enclose a square ride-sharing pickup zone, given the zone's side length in meters. The barriers must run continuously along all four sides of the designated area to ensure passenger safety and orderly vehicle queuing.
    

    """
    perimeter = 4 * a
    return perimeter