It is usually assumed that the transport properties of atoms and molecules in excited electronic states are nearly the same as in the ground state. Using available experimental and theoretical results for interactions between carbon atoms in excited electronic states, reasonably exact calculations of the transport properties of excited state carbon atoms are obtained. These results are compared with results for several models that have been used to estimate transport properties for excited species. It appears that the assumption mentioned above is correct but that the models do not predict the transport properties of excited species very accurately.