  We investigated the in-plane transport properties of the Fe-based
superconductor Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ with a wide composition range
$0 \leq x \leq 0.55$. We show that the doping dependence of the Hall
coefficient is well-described by the Boltzmann equation for a two-band system
with a rigid-band approximation. We successfully deduced transport parameters,
which suggested that holes with heavier mass conduct more smoothly than
electrons. Moreover, the temperature variation of the Hall coefficient
indicated that an anomalous coherent state characterized by heavy
quasiparticles in hole bands evolved below $\sim100$ K, predominantly in the
optimal and overdoped regions. We argue that this phenomenon can be understood
in relation to the pseudopeak structure observed in angle-resolved
photoemission spectroscopy.
