Electron spin-lattice, T₁, and spin-spin, T₂, relaxation times in polyacetylene samples have been measured by a saturation method at 2-mm waveband EPR at 90-330 K. Temperature dependences of the intrachain diffusion and interchain hopping rates in trans-(CH)_x are evaluated. Spin dynamics in pristine trans-(CH)_x does not agree with the predictions of the soliton model, but it is in a good agreement with the intersoliton isoenergetic electron hopping model of charge transport predicted by Kivelson