Driving on snow presents specific challenges due to the terrain conditions. One of the main problems is that **tires have less grip** on the snowy surface, causing the wheels to **skid**. This means that when trying to start the vehicle, the wheels may spin without moving forward, losing traction and preventing the vehicle from moving properly.

Additionally, the snow can be soft and allow the wheels to **sink**, which further complicates starting the vehicle. This lack of traction and sinking in the snow are the reasons why it is difficult to start a vehicle in these conditions. To mitigate these problems, it is recommended to start with the wheels straight and choose a gear that allows for a smoother and more controlled start.