During her time with the Victor Film Company and later, Florence Lawrence demonstrated an interest in automobiles and began working on innovative features for them.

Florence Lawrence is credited with inventing the 'auto signaling arm', a precursor to the modern turn signal. This device, mounted on the rear fender, could be raised or lowered to indicate which direction the driver intended to turn.

Lawrence also designed one of the first brake signals. When the driver applied the brakes, a signal would light up at the rear of the car to alert drivers behind.

Despite these important contributions, Florence Lawrence never patented her inventions. Consequently, she received little or no recognition for her innovative designs, and they were later developed and commercialized by others.