Calibration of time-to-collision thresholds under weak light conditions

The invention relates to a method of modifying a time-of-collision threshold, the method comprising: receiving data and images of an object from image capture devices and non-visual sensors within an automobile, infrastructure cameras, and other image capture devices within an automobile; determining an ambient light level and a color of the object; comparing the ambient light level to a predetermined ambient light level threshold; determining a standard collision time threshold; sending a standard collision time threshold to the collision avoidance system when the ambient light level is at least a predetermined ambient light level; determining a standard collision time threshold, an illumination coefficient and a color coefficient; applying the illumination coefficient and the color coefficient to a standard collision time threshold; calculating a modified collision time threshold value; and sending the modified collision time threshold to the collision avoidance system when the ambient light level is less t