We consider one-dimensional random walks in random environment which are transient to the right. Our main interest is in the study of the sub-ballistic regime, where at time $n$ the particle is typically at a distance of order $O(n^kappa)$ from the origin, $kappain(0,1)$. We investigate the probabilities of moderate deviations from this behaviour. Specifically, we are interested in quenched and annealed probabilities of slowdown (at time $n$, the particle is at a distance of order $O(n^{ u_0})$ from the origin, $ u_0in (0,kappa)$), and speedup (at time $n$, the particle is at a distance of order $n^{ u_1}$ from the origin, $ u_1in (kappa,1)$), for the current location of the particle and for the hitting times. Also, we study probabilities of backtracking: at time $n$, the particle is located around $(-n^ u)$, thus making an unusual excursion to the left. For the slowdown, our results are valid in the ballistic case as well.
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