Humans already have problems with the aspect of driving in two dimensions (forward and backwards, side to side), adding in the up and down aspect would make "driving" or flying as it would be, much more difficult; however, this problem might be solved via the sole use of self-flying and self-driving cars.[33] In mid-air collisions and mechanical failures, the aircraft could fall from the sky or go through an emergency landing, resulting in deaths and property damage.[34] In addition, poor weather conditions, such as low air density, lightning storms and heavy rain, snow or fog could be challenging and affect the aircraft's aerodynamics.[35]