What is the primary danger when riding on unpaved sand or silt (dust) roads in southern and western Afghanistan?

1. Front tire plowing and sinking in loose sand, causing violent handlebar twisting and instant front-end washouts
2. Sand grips better than asphalt because the tyre sinks into it
3. The rear wheel loses drive entirely, so the machine simply stops
4. Sand is only a hazard when the surface is wet