The corridor’s main function of speed is derived its etymology. In the 14th century, the corridor was not a place, but a person. From “currere,” to run, the corridóre first described a courier, and eventually referred to the pathways above fortified walls, which enabled the transfer of messages. With the invention of the trace italienne fortification system in the 15th century, military leaders relocated troops to ditches at the bottom of the wall. The corridor followed. In the 17th century, architects interiorized the corridor. By The 19th century corridoio described a passage within a building. The corridor ceased to be an urban element, but still maintained a close relationship to the dimensions of the human body and the function of speed. But now it occurred within buildings rather than between them. Architects gradually abandoned the corridor after its heyday in the 19th century. However, escalating building heights of the 20th century brought increasing demands exit corridor.