  The recently suggested correspondence between domain dynamics of traffic
models and the asymmetric chipping model is reviewed. It is observed that in
many cases traffic domains perform the two characteristic dynamical processes
of the chipping model, namely chipping and diffusion. This correspondence
indicates that jamming in traffic models in which all dynamical rates are
non-deterministic takes place as a broad crossover phenomenon, rather than a
sharp transition. Two traffic models are studied in detail and analyzed within
this picture.
