Division 1.3.1.4 It shall be verified by the technical service, to the satisfaction of the type-approval authority that aerodynamic devices and equipment referred to in points 1.3.1.1, 1.3.1.2 and 1.3.1.3 positioned in both, the in-use and retracted or folded positions, do not impair the driver’s forward field of vision and the windscreen wash and wipe functions, as well as do not significantly impair the cooling and ventilation of the powertrain, exhaust system, braking system, occupant cabin and loading area. All other applicable requirements relating to the vehicle systems shall be fully complied with when the devices and equipment are placed in both their in-use and retracted or folded positions.F1

By way of derogation concerning the applicable requirements relating to front underrun protection, the horizontal distances between the foremost part of the vehicle as fitted with aerodynamic devices and equipment and its front underrun protective device as well as the rear of the rear underrun protection device and the rear extremity of the vehicle as fitted with aerodynamic devices and equipment may be measured without taking the devices and equipment into account on condition that at the rear they exceed 200 mm in length and they are in the in-use condition and that at the front and rear the fundamental sections of the elements placed at a height ≤ 2,0 m above the ground measured in unladen condition are made of material having a hardness of < 60 Shore (A). Narrow ribs, tubing and metal wire forming a frame or substrate to support the fundamental sections of the elements shall not be taken into account when determining the hardness. However, in order to eliminate the risk of injuries and penetration of other vehicles in the event of a collision, any ends of such ribs, tubing and metal wire shall not be directed forward at the front and rearward at the rear of the vehicle, with the device and equipment both in the retracted or folded and the in-use positions.

As alternative to the derogation concerning the rear underrun protection device referred to in the previous paragraph, the horizontal distances between the rear of the rear underrun protection device and the rear extremity of the vehicle as fitted with aerodynamic devices and equipment may be measured without taking the aerodynamic devices and equipment into account provided that they exceed 200 mm in length, they are in the in-use condition and those devices or equipment comply with the test provisions set out in Appendix 4.

The horizontal distances between the rear of the rear underrun protection device and the rear extremity of the vehicle shall however be measured with the aerodynamic devices and equipment positioned in the retracted or folded position or take into account the resulting projection length in accordance with point 1.6.1 of Appendix 4, if this length exceeds that of the retracted or folded position.