A method of determining by a computer system at least one current value of at least one occupancy parameter relating to a portion of a space located in the vicinity of a motorized land vehicle, the method comprising the steps of: - obtaining a previous value of the occupancy parameter, a current value of an occupancy counter and a current value of a time-out counter, and - determining the current occupancy parameter value using the previous occupancy parameter value, the current occupancy counter value and the current timer counter value; and said method further comprises: - a step of determining whether the previous value of the occupancy parameter characterizes an indefinite judgement as to the occupancy of said portion and, when this is the case, a step of using data generated on the basis of a signal emitted by a sensing device arranged in the vehicle to determine the current value of the occupancy parameter, a step of incrementing the occupancy counter and a step of resetting the timer counter; - a step consisting in, when the previous value of the occupancy parameter characterizes a defined assessment of the occupancy of said portion, determining whether a signal establishing that an object is present within said portion is emitted by the detection device, and, when this is the case, a step consisting in using a predictive model to determine the current value of the occupancy parameter, a step consisting in incrementing the occupancy counter and a step consisting in resetting the timer counter; - a step of, when the detection device emits a signal establishing that no object is present within said portion, determining whether said portion is located within the detection field of the detection device; characterized in that the method comprises - a step of, when said portion is located within the detection field of the detection device, determining whether the occupancy counter is greater than a first predefined threshold and, when this is the case, a step of determining whether the timer counter is less than or equal to a second predefined threshold and, when this is the case, a step of assigning the previous value of the occupancy parameter to the current value of the occupancy parameter and a step of incrementing the timer counter. - obtaining a previous value of the occupancy parameter, a current value of an occupancy counter and a current value of a time-out counter, and - determining the current occupancy parameter value using the previous occupancy parameter value, the current occupancy counter value and the current timer counter value; and - a step of determining whether the previous value of the occupancy parameter characterizes an indefinite judgement as to the occupancy of said portion and, when this is the case, a step of using data generated on the basis of a signal emitted by a sensing device arranged in the vehicle to determine the current value of the occupancy parameter, a step of incrementing the occupancy counter and a step of resetting the timer counter; - a step consisting in, when the previous value of the occupancy parameter characterizes a defined assessment of the occupancy of said portion, determining whether a signal establishing that an object is present within said portion is emitted by the detection device, and, when this is the case, a step consisting in using a predictive model to determine the current value of the occupancy parameter, a step consisting in incrementing the occupancy counter and a step consisting in resetting the timer counter; - a step of, when the detection device emits a signal establishing that no object is present within said portion, determining whether said portion is located within the detection field of the detection device; characterized in that the method comprises - a step of, when said portion is located within the detection field of the detection device, determining whether the occupancy counter is greater than a first predefined threshold and, when this is the case, a step of determining whether the timer counter is less than or equal to a second predefined threshold and, when this is the case, a step of assigning the previous value of the occupancy parameter to the current value of the occupancy parameter and a step of incrementing the timer counter.