Despite the fact that fully-developed laminar pipe flow (PF) is linearly stable, in reality laminar-to-turbulent transition of flow start to occur in pipes at various Reynolds numbers (Re), depending on the existing disturbances in the flow. When a localized disturbance is induced in the flow, at low Re, certain flow structures starts to occur prior to transition and during transition. Among those flow structures, turbulent puff and slug structures have been known for a long time. Recently, it was shown numerically that large scale flow structures, the so called traveling waves (TW), occur prior to transition. Despite the numerical discovery of TW, it is still a challenge to investigate these flow structures experimentally, because of the lack of knowledge on the types and the amplitude of disturbances generating such structures. Moreover, the evolution of the transitional structures with increasing Re has not been fully understood. For example, whether TW evolve to a turbulent puff is not known, if it evolves, next it should be found whether only certain type of TW develops to a turbulent puff or slug. In the last decade at LSTM-Erlangen, the kinematical consideration on the anisotropy of velocity fluctuations have shown that anisotropy invariants of velocity fluctuations follow certain paths during transition. However, no effort has been made to converge the results obtained from the dynamics of the transitional flow structures and the kinematical considerations. Hence, the proposed project aims at investigating the generation mechanism of TW in pipes, their connection to turbulent transitional structures puff and slug and the border between them, the connection between the dynamical and kinematical findings on transitional structures, and at establishing strategies to control transition. The investigations will be of experimental nature. Velocity measurements with hot-wire anemometry and stereo PIV will be conducted, pressure transients will be measured for the direct determination of lifetime of puffs. Flow visualization coupled with pattern recognition and optimization algorithm will be employed to find optimum disturbance parameters for each type of TW, so that the connection between the disturbance and the generated TW will be efficiently established. This data would help to construct a map showing the border between the laminar and turbulent states. Being able to generate TW of different shapes in a reproducible manner allows us, at the second phase of the project, to investigate quantitatively the velocity field within the TW and in the development of TW along the pipe till it becomes turbulent. Hence, the data made available by the experiments would help to bridge the dynamical and kinematical considerations and construct strategies to control transition. Ultimately, the measured profiles of turbulent stresses and their anisotropy, probability and lifetime statistics, and the peculiarities of transitional flow structures will be analyzed together with those found in Taylor-Couette flows (TC) and Rayleigh-Benard convection (RB), to show the common transport mechanisms in those flows.