Instant speed: speed of a vehicle at a given point in time, shown on the speedometer. 2. Pace: the speed of a column or convoy regulated by the guide to maintain the prescribed average speed. 3. Average speed: produce of the number of kilometers to drive by the planned duration of the trip, once the time allotted to halts lasting one hour or more have been suppressed. The average speed is a general planning data for staffs.

English thesaurus

instant ['ɪnstənt] abbr.