The concept of the mean free path, i.e., the mean distance between subsequent collisions of DNA molecules with gel fibers, is introduced to the model description of the geometration effect. A new formula is derived for the correction to the velocity v of long molecules in gel due to the geometration process: v = v(r)/(1+3s/4b), where v(r) is the velocity without geometration, s is the molecule length and b is the mean free path of molecules. The peak dispersion sigma(x) is evaluated with the same model approach. We get the contribution to the bandwidth from the geometration effect. For b = s the bandwidth is about 2(sx)(1/2), where x is the length of the path of the molecules in gel. The results are compared with experimental data on the linearized plasmid pKecNOS in 4% agarose gel.