The ESR linewidths in polythiophene, poly(3-methylthiophene) and polypyrrole doped with ClO 4 - and AsF 6 - were measured as a function of temperature to study the dynamics of charged carriers with spin. The temperature dependence of the ESR linewidth can be understood in terms of the Elliott mechanism, characteristic for metallic electrons. Such an interpretation leads us to conclude that the electron scattering is not governed by potential of dopants, but by that on polymer backbone. In addition, the temperature dependence of the resistance ratio r V S C obtained by voltage-shorted-compaction method was found to coincide with that of the linewidth qualitatively. We show that a simple one-dimensional model for the resistivity that takes the electron scattering only by 2k F -phonons into consideration can qualitatively well explain both the data.