The authors give a phenomenological formula for interedge channel scattering (IES) in the multichannel case. The equilibrium length over which the population of different channels is equilibrated is extracted from the experiments. The four-terminal resistances for the transport through edge and bulk currents are calculated in real conductors by taking into account scattering which equilibrates different transport channels. Negative resistances are found in the simulation. This makes it clear that the coexistence of bulk and edge states, together with interedge scattering, is the origin of the negative resistances observed in a variety of samples.