1. A method of detecting an incident on a portion of route situated in a scene said portion of route is suitable for having objects travelling therealong, and the method using a video camera controllable in one of azimuth, elevation and field of view and having a target constituting an optoelectronic converter of a real optical image of the scene, said target being controlled by a programmable processor member, said process detecting incidents comprising: A) having said programmable processing member determine that said video camera is substantially stationary in relation to said scene by i) selecting at least one point on a current real image of said scene, outside of said portion of said route; ii) comparing said at least one point on said current real image with said at least one point on at least one of a set of immediate previous targets of a stored image; iii) determining that said at least one point is approximately at the same position in said current real image as in at least one of the set of immediate previous targets of the stored image; iv)a) upon failure to determine the same position in step iii, re-execute steps i) through iii) with at least one other point; and iv)b) upon determining the same position in step iii), proceed to step B) B) having said programmable processor member process said current real images to detect incidents.