8.8. The width of the FUPD shall at no point exceed the width of the mudguards covering the wheels of the foremost axle nor shall it be more than 100 mm shorter on either side than the foremost axle measured at the outermost points of the tyres, excluding the bulging of the tyres close to the ground (see figure 1), or 200 mm shorter on either side, measured from the outermost points of the access steps to the driver's cabin.