The invention pertains to a method for estimating the attention level of the driver of a vehicle in a traffic lane, comprising the following steps: —the continuous capture of images (10) of the ground, —the reconstruction of an aerial view (11, 12) of a ground segment at successive instants t, —the reconstruction of an aerial view (11, 12) of a road segment at successive current instants t, —the estimation of the lateral position of the vehicle (100) in the reconstructed aerial view (11, 12), and the storage of said estimated positions of the vehicle, —the determination of an estimated attention level of the driver at a past instant t3, as a function: o of the evolution of the lateral position of the vehicle, o of the analysis of the profile of a road portion at least partially situated upstream of the vehicle at the instant t3.