The air contamination content was studied of the air samples taken from the driver's cabs of different vehicles at the time of sharp braking. The air samples contained: CO (0.7-9.7 mg/m3); n-hydrocarbons + divinyl (6.4-130.0 mg/m3); aromatic hydrocarbons (3.6-26.8 mg/m3); acrylonitrile (0.5-1.0 mg/m3) H2S (0.23-0.9 mg/m3); SO2 (1.5-7.05 mg/m3).