The model of the atmospheric admixture dispersal, in which the fields of wind velocity, temperature, and air humidity are determined using a closed system of the Navier-Stokes equations, is considered. The problem on determining the pollution of an anticipated residential microdistrict in the Ob town by car exhausts coming from Novosibirsk-Tolmachevo highway under construction is considered as a practical example. The performed series of calculations has enabled choosing an optimal town-planning decision to minimize the impact of car exhausts on the ecological situation in the microdistrict.