Fine structures of the unstable waves and the electron density profiles resulting from nonlinear spatial transport are studied numerically for a collisional flute mode instability. It is confirmed that the nonlinear transport produces regular pulse trains in both the electron density and wave amplitude profiles in the direction perpendicular to the electron drift (in the direction of the density gradient). Fourier spectral analysis of the nonlinear structure in that direction indicates two major spectral peaks. The main peak is the fundamental mode which leads to overall flattening of the density distribution in the entire unstable region. The second peak corresponds to the generated small‐scale pulses resulting from a nonlinear instability associated with a strong wave‐induced transport. In the steady state the pulses tend to merge and be smeared out to form a plateau in the density profile. These indicate the presence of two different, steady and pulsative, transports. Examination of the spatial structure finds that the pulse width is roughly the same size as the dominant wavelength of the primary wave which propagates in the direction of the drift. It is further found that the observed nonlinear mode can be explained by a nonlinear transport equation of the formnt+(n2)z+ky−2(n2)zzz@qL=0, wherekyis the wavelength of the dominant primary wave propagating in the direction of the drift andzdenotes the coordinate perpendicular to the drift.