Section 587.18 - Dimensions of fixed rigid barrier(a) The fixed rigid barrier has a mass of not less than 7 * 104 kg (154,324 lb).(b) The height of the fixed rigid barrier is at least as high as the highest point on the vehicle at the intersection of the vertical transverse plane tangent to the forwardmost point of both front tires, when the tires are parallel to the longitudinal centerline of the vehicle, and the vertical plane through the longitudinal centerline of the vehicle.