  We compute the longitudinal dc conductivity and the Hall conductivity in a
two-dimensional metal with spiral magnetic order. Scattering processes are
modeled by a momentum-independent relaxation rate $\Gamma$. We derive
expressions for the conductivities, which are valid for arbitrary values of
$\Gamma$. Both intraband and interband contributions are fully taken into
account. For small $\Gamma$, the ratio of interband and intraband contributions
is of order $\Gamma^2$. In the limit $\Gamma \to 0$, the conductivity formulas
assume a simple quasiparticle form, as derived by Voruganti et. al. [Phys. Rev.
B 45, 13945 (1992)]. Using the complete expressions, we can show that
relaxation rates in the regime of recent transport experiments for cuprate
superconductors in high magnetic fields are sufficiently small to justify the
application of these simplified formulas. The longitudinal conductivity
exhibits a pronounced nematicity in the spiral state. The drop of the Hall
number as a function of doping observed recently in several cuprate compounds
can be described with a suitable phenomenological ansatz for the magnetic order
parameter.
