What is the physical hazard of carrying loose items (like heavy tools, bottles, or cans) on the cab dashboard or floor?

1. They will decrease the vehicle's maximum speed by 10 mph
2. They can slide under the pedals under braking, blocking pedal operation, or act as dangerous projectiles in a collision
3. They block the vehicle's engine exhaust pipe
4. They cause the digital tachograph to reject the driver's card