Vehicles require thrust forces, generated at the tires, to initiate and maintain motion. These forces
are usually referred to as tractive forces or the tractive force requirement. If the required tractive
force (F) is broken into components the major components of the resisting forces to motion are
comprised of acceleration forces (Faccel = ma & I forces), Gradeability requirements (Fgrade),
Aerodynamic loads (Faero) and chassis losses (Froll resist ).