The method of spatial averaging is used to analyze the equations for electrolyte transport across charged cylindrical pores. Using this approach, an analytical expression for the radial potential profile is obtained which is valid when the radial deviations of the electrical potential from the area-averaged potential are small. This expression can be integrated analytically, thus eliminating the need for much of the computational effort required in the usual space-charge models. Furthermore, it is shown that this analytical expression for the radial potential profile leads to model predictions for membrane permeability, osmotic flow, conductivity, streaming potential, and concentration potential in solutions of binary electrolytes which match the predictions from the space-charge model using a numerical solution to the Poisson-Boltzmann equation when the radial deviation of the potential is as high as 50 mV. Unlike most previous models of electrolyte transport in charged capillaries, this approach allows one to easily model systems of three or more ions while still taking into account the effects of the radial profiles of potential, concentration, and velocity.