1. A method on analyzing a location of driver visual interest derived from observation of driver physiological orientation in a vehicle, the method comprising: obtaining data descriptive of a plurality of driver gaze direction instances, wherein each driver gaze direction instance is defined by a data set; processing the data using a computer-based processor; classifying a plurality of the driver gaze direction instances as either 00 location or off-location in preparation for further analysis related to the location of driver visual interest; clustering data derived from the classified driver gaze direction instances; characterized in that transforming each of the plurality of classified driver gaze direction instances into one of two binary values representative of whether the respective driver gaze direction instance is on-location or off-location thus forming a classification signal which determines in each sample or unit of time whether the location of driver visual interest is on-location or off-location; computing a glance frequency by counting the number of on-and off intervals in the classification signal; and computing a glance duration by regarding a start and end of each continuous segment classified in the same way.