Article presents the implementation of relaxation time approximation models in the calculation of Boltzmann transport in PAOFLOW 2.0 and applies those to model band-structures. In addition, using a self-consistent fitting of the model parameters to experimental conductivity data, the authors provide a flexible tool to extract scattering rates with high accuracy. They illustrate the approximations using simple models and then apply the method to GaAs, Si, Mg₃Sb₂, and CoSb₃.