The one and two-dimensional model discussed in this paper give insight in the principle nature of traffic jams on roads and in cities. In most models, the traffic flow is significantly simplified, which allowed analytical and numerical modeling. However, properties of individual drivers and cars as well as road conditions were not taken into account. Considering these factors will lead to more realistic models for the traffic flow. On the other hand, only a few comparisons with experimental data have been made. Experimental finding like reported by Kerner el al.  will certainly have an influence on the modeling and understanding of traffic flow.