In the analysis of the influence of transport саrs fluctuations on сontrollability of curvilinear movement dependence of different types of fluctuations on the speed of movement of the car on roughness of the district is most important. The analysis of the right parts of the differential equations of fluctuations of the multibasic high-speed transport car on the basis of research of limits of these expressions for harmonious indignation is carried out. The conclusion that with increase in speed of movement on a cross-country terrain the maximum indignations causing it longitudinally angular fluctuations become insignificant in comparison with the indignations causing vertical fluctuations of the center of mass of the car is received.