Device (10) for vehicle driving evaluation comprising: A means (11) to obtain at least one physical parameter whereby it possible at any time to determine the value of the speed and instantaneous acceleration of a traveling vehicle; A calculation and comparison unit (12) whereby it is possible, from said physical parameter, to calculate an effective parameter that depends on said instantaneous acceleration and to compare said effective parameter with a reference parameter; A driving evaluation unit (13), whereby it is possible to generate a vehicle driving energy score by measuring the variance between said effective parameter and said reference parameter. Corresponding vehicle driving evaluation process.