Proper driving requires a proper posture to bring comfort to drivers. A problem that commonly exists in driving is incorrect driving posture which can cause discomfort to the driver, especially when interacting with automotive pedals. Research on contraction of tibialis anterior (TA) muscle on driver's posture based on the knee angle less than 101º in a position of pressing and releasing a pedal was conducted to investigate and overcome this problem. This is a field experiment study and surface electromyography (sEMG) is used in collecting data on the TA muscle. The procedure of collecting data on the TA muscle before and after experiments follows the Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles (SENIAM) recommendations. The result of the experiment shows that there is a strong negative relationship between driver's postures in nature based on the angle of the knee with TA muscle contractions, where the Pearson correlation coefficient (r) is - .993. While the temporal analysis measurements based on Maximum Voluntary Isometric Contraction (MVIC) 60% in a position of releasing a pedal exceeding rms μV 39.38, are 39.71 and 40.25 respectively. On the other hand, MVIC 2% rms μV values: 1.19 and 1.2 are obtained in the position of pressing the pedal. The knee angle with TA muscle contractions is significant [F (1, 10) = 660, p