A computer-implement method (200) of predicting a drag area (as function of airattack angle) of a vehicle combination after hypothetically changing an exterior shape of the vehicle combination from a first exterior shape to a second exterior shape is provi...

A deceleration factor estimation apparatus (1) estimating a deceleration factor of a vehicle (2) includes: a driving force acquisition unit (62) that obtains a driving force of the vehicle (2); a speed acquisition unit (60) that obtains a speed of the vehi...