Technological developments have two significant consequences over transportation modes. The first involves the emergence of new modes, and the second concerns an improvement of their operational capabilities, such as speed. Many modes follow a similar pattern where a significant growth of their operational speed takes place in their introduction phase. Once technical constraints are solved, and modal networks expanded, operational speeds reach a threshold that remains until the mode becomes obsolete and is abandoned (stagecoach, clipper ships, and liners) or new technology is introduced, and a new wave of technical improvements incurs (jet planes, high-speed trains). Once the operational speed has been reached, the focus is to improve modal efficiency, particularly energy use, to reduce the operation costs and expand the market reach of the mode.